* Re: BUG: libkcapi tests trigger sleep-in-atomic bug in VMX code (ppc64)
[not found] ` <CAAUqJDt_y04ts7Aq0U0fhXYRus2ckkEohBTkga0pjqfoQaBOCA@mail.gmail.com>
@ 2018-08-21 15:03 ` Christophe LEROY
2018-08-21 15:16 ` [PATCH] crypto: vmx - Fix sleep-in-atomic bugs Ondrej Mosnacek
2018-08-22 6:26 ` [PATCH v2] " Ondrej Mosnacek
2 siblings, 0 replies; 17+ messages in thread
From: Christophe LEROY @ 2018-08-21 15:03 UTC (permalink / raw)
To: Ondrej Mosnáček, Stephan Mueller
Cc: Herbert Xu, Paul Mackerras, linux-crypto, marcelo.cerri, linuxppc-dev
Le 21/08/2018 à 16:38, Ondrej Mosnáček a écrit :
> ut 21. 8. 2018 o 16:18 Stephan Mueller <smueller@chronox.de> napísal(a):
>> Am Dienstag, 21. August 2018, 14:48:11 CEST schrieb Ondrej Mosnáček:
>>
>> Hi Ondrej, Marcelo,
>>
>> (+Marcelo)
>>
>>> Looking at crypto/algif_skcipher.c, I can see that skcipher_recvmsg()
>>> holds the socket lock the whole time and yet passes
>>> CRYPTO_TFM_REQ_MAY_SLEEP to the cipher implementation. Isn't that
>>> wrong?
>>
>> I think you are referring to lock_sock(sk)?
>>
>> If so, this should not be the culprit: the socket lock is in essence a mutex-
>> like operation with its own wait queue that it allowed to sleep. In
>> lock_sock_nested that is called by lock_sock it even has the call of
>> might_sleep which indicates that the caller may be put to sleep.
>>
>> Looking into the code (without too much debugging) I see in the function
>> p8_aes_cbc_encrypt that is part of the stack trace the call to
>> preempt_disable() which starts an atomic context. The preempt_enable() is
>> invoked after the walk operation.
>>
>> The preempt_disable increases the preempt_count. That counter is used by
>> in_atomic() to check whether we are in atomic context.
>>
>> The issue is that blkcipher_walk_done may call crypto_yield() which then
>> invokes cond_resched if the implementation is allowed to sleep.
>
> Indeed, you're right, the issue is actually in the vmx_crypto code. I
> remember having looked at the 'ctr(aes)' implementation in there a few
> days ago (I think I was trying to debug this very issue, but for some
> reason I only looked at ctr(aes)...) and I didn't find any bug, so
> that's why I jumped to suspecting the algif_skcipher code... I should
> have double-checked :)
>
> It turns out the 'cbc(aes)' (and actually also 'xts(aes)')
> implementation is coded a bit differently and they both *do* contain
> the sleep-in-atomic bug. I will try to fix them according to the
> correct CTR implementation and send a patch.
CC: linuxppc-dev@lists.ozlabs.org <linuxppc-dev@lists.ozlabs.org>
>
> Thanks,
> Ondrej
>
>> @Marcelo: shouldn't be the sleep flag be cleared when entering the
>> preempt_disable section?
>>
>> Ciao
>> Stephan
>>
>>
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: BUG: libkcapi tests trigger sleep-in-atomic bug in VMX code (ppc64)
@ 2018-08-21 15:03 ` Christophe LEROY
0 siblings, 0 replies; 17+ messages in thread
From: Christophe LEROY @ 2018-08-21 15:03 UTC (permalink / raw)
To: Ondrej Mosnáček, Stephan Mueller
Cc: marcelo.cerri, linux-crypto, Herbert Xu, Benjamin Herrenschmidt,
Paul Mackerras, Michael Ellerman, linuxppc-dev
Le 21/08/2018 à 16:38, Ondrej Mosnáček a écrit :
> ut 21. 8. 2018 o 16:18 Stephan Mueller <smueller@chronox.de> napísal(a):
>> Am Dienstag, 21. August 2018, 14:48:11 CEST schrieb Ondrej Mosnáček:
>>
>> Hi Ondrej, Marcelo,
>>
>> (+Marcelo)
>>
>>> Looking at crypto/algif_skcipher.c, I can see that skcipher_recvmsg()
>>> holds the socket lock the whole time and yet passes
>>> CRYPTO_TFM_REQ_MAY_SLEEP to the cipher implementation. Isn't that
>>> wrong?
>>
>> I think you are referring to lock_sock(sk)?
>>
>> If so, this should not be the culprit: the socket lock is in essence a mutex-
>> like operation with its own wait queue that it allowed to sleep. In
>> lock_sock_nested that is called by lock_sock it even has the call of
>> might_sleep which indicates that the caller may be put to sleep.
>>
>> Looking into the code (without too much debugging) I see in the function
>> p8_aes_cbc_encrypt that is part of the stack trace the call to
>> preempt_disable() which starts an atomic context. The preempt_enable() is
>> invoked after the walk operation.
>>
>> The preempt_disable increases the preempt_count. That counter is used by
>> in_atomic() to check whether we are in atomic context.
>>
>> The issue is that blkcipher_walk_done may call crypto_yield() which then
>> invokes cond_resched if the implementation is allowed to sleep.
>
> Indeed, you're right, the issue is actually in the vmx_crypto code. I
> remember having looked at the 'ctr(aes)' implementation in there a few
> days ago (I think I was trying to debug this very issue, but for some
> reason I only looked at ctr(aes)...) and I didn't find any bug, so
> that's why I jumped to suspecting the algif_skcipher code... I should
> have double-checked :)
>
> It turns out the 'cbc(aes)' (and actually also 'xts(aes)')
> implementation is coded a bit differently and they both *do* contain
> the sleep-in-atomic bug. I will try to fix them according to the
> correct CTR implementation and send a patch.
CC: linuxppc-dev@lists.ozlabs.org <linuxppc-dev@lists.ozlabs.org>
>
> Thanks,
> Ondrej
>
>> @Marcelo: shouldn't be the sleep flag be cleared when entering the
>> preempt_disable section?
>>
>> Ciao
>> Stephan
>>
>>
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: BUG: libkcapi tests trigger sleep-in-atomic bug in VMX code (ppc64)
2018-08-21 15:03 ` Christophe LEROY
@ 2018-08-21 15:12 ` Marcelo Henrique Cerri
-1 siblings, 0 replies; 17+ messages in thread
From: Marcelo Henrique Cerri @ 2018-08-21 15:12 UTC (permalink / raw)
To: Christophe LEROY
Cc: Herbert Xu, Stephan Mueller, Ondrej Mosnáček,
Paul Mackerras, linux-crypto, Paulo Flabiano Smorigo,
linuxppc-dev
[-- Attachment #1: Type: text/plain, Size: 2770 bytes --]
CC: Paulo Flabiano Smorigo <pfsmorigo@linux.vnet.ibm.com>
Yes, I do believe that CTR is doing it right. Preemption only needs to be
disabled during the aes_p8_cbc_encrypt() call, to avoid trashing the
VSX registers during the AES operation.
--
Regards,
Marcelo
On Tue, Aug 21, 2018 at 05:03:50PM +0200, Christophe LEROY wrote:
>
>
> Le 21/08/2018 à 16:38, Ondrej Mosnáček a écrit :
> > ut 21. 8. 2018 o 16:18 Stephan Mueller <smueller@chronox.de> napísal(a):
> > > Am Dienstag, 21. August 2018, 14:48:11 CEST schrieb Ondrej Mosnáček:
> > >
> > > Hi Ondrej, Marcelo,
> > >
> > > (+Marcelo)
> > >
> > > > Looking at crypto/algif_skcipher.c, I can see that skcipher_recvmsg()
> > > > holds the socket lock the whole time and yet passes
> > > > CRYPTO_TFM_REQ_MAY_SLEEP to the cipher implementation. Isn't that
> > > > wrong?
> > >
> > > I think you are referring to lock_sock(sk)?
> > >
> > > If so, this should not be the culprit: the socket lock is in essence a mutex-
> > > like operation with its own wait queue that it allowed to sleep. In
> > > lock_sock_nested that is called by lock_sock it even has the call of
> > > might_sleep which indicates that the caller may be put to sleep.
> > >
> > > Looking into the code (without too much debugging) I see in the function
> > > p8_aes_cbc_encrypt that is part of the stack trace the call to
> > > preempt_disable() which starts an atomic context. The preempt_enable() is
> > > invoked after the walk operation.
> > >
> > > The preempt_disable increases the preempt_count. That counter is used by
> > > in_atomic() to check whether we are in atomic context.
> > >
> > > The issue is that blkcipher_walk_done may call crypto_yield() which then
> > > invokes cond_resched if the implementation is allowed to sleep.
> >
> > Indeed, you're right, the issue is actually in the vmx_crypto code. I
> > remember having looked at the 'ctr(aes)' implementation in there a few
> > days ago (I think I was trying to debug this very issue, but for some
> > reason I only looked at ctr(aes)...) and I didn't find any bug, so
> > that's why I jumped to suspecting the algif_skcipher code... I should
> > have double-checked :)
> >
> > It turns out the 'cbc(aes)' (and actually also 'xts(aes)')
> > implementation is coded a bit differently and they both *do* contain
> > the sleep-in-atomic bug. I will try to fix them according to the
> > correct CTR implementation and send a patch.
>
> CC: linuxppc-dev@lists.ozlabs.org <linuxppc-dev@lists.ozlabs.org>
>
> >
> > Thanks,
> > Ondrej
> >
> > > @Marcelo: shouldn't be the sleep flag be cleared when entering the
> > > preempt_disable section?
> > >
> > > Ciao
> > > Stephan
> > >
> > >
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^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: BUG: libkcapi tests trigger sleep-in-atomic bug in VMX code (ppc64)
@ 2018-08-21 15:12 ` Marcelo Henrique Cerri
0 siblings, 0 replies; 17+ messages in thread
From: Marcelo Henrique Cerri @ 2018-08-21 15:12 UTC (permalink / raw)
To: Christophe LEROY
Cc: Ondrej Mosnáček, Stephan Mueller, linux-crypto,
Herbert Xu, Benjamin Herrenschmidt, Paul Mackerras,
Michael Ellerman, linuxppc-dev, Paulo Flabiano Smorigo
[-- Attachment #1: Type: text/plain, Size: 2770 bytes --]
CC: Paulo Flabiano Smorigo <pfsmorigo@linux.vnet.ibm.com>
Yes, I do believe that CTR is doing it right. Preemption only needs to be
disabled during the aes_p8_cbc_encrypt() call, to avoid trashing the
VSX registers during the AES operation.
--
Regards,
Marcelo
On Tue, Aug 21, 2018 at 05:03:50PM +0200, Christophe LEROY wrote:
>
>
> Le 21/08/2018 à 16:38, Ondrej Mosnáček a écrit :
> > ut 21. 8. 2018 o 16:18 Stephan Mueller <smueller@chronox.de> napísal(a):
> > > Am Dienstag, 21. August 2018, 14:48:11 CEST schrieb Ondrej Mosnáček:
> > >
> > > Hi Ondrej, Marcelo,
> > >
> > > (+Marcelo)
> > >
> > > > Looking at crypto/algif_skcipher.c, I can see that skcipher_recvmsg()
> > > > holds the socket lock the whole time and yet passes
> > > > CRYPTO_TFM_REQ_MAY_SLEEP to the cipher implementation. Isn't that
> > > > wrong?
> > >
> > > I think you are referring to lock_sock(sk)?
> > >
> > > If so, this should not be the culprit: the socket lock is in essence a mutex-
> > > like operation with its own wait queue that it allowed to sleep. In
> > > lock_sock_nested that is called by lock_sock it even has the call of
> > > might_sleep which indicates that the caller may be put to sleep.
> > >
> > > Looking into the code (without too much debugging) I see in the function
> > > p8_aes_cbc_encrypt that is part of the stack trace the call to
> > > preempt_disable() which starts an atomic context. The preempt_enable() is
> > > invoked after the walk operation.
> > >
> > > The preempt_disable increases the preempt_count. That counter is used by
> > > in_atomic() to check whether we are in atomic context.
> > >
> > > The issue is that blkcipher_walk_done may call crypto_yield() which then
> > > invokes cond_resched if the implementation is allowed to sleep.
> >
> > Indeed, you're right, the issue is actually in the vmx_crypto code. I
> > remember having looked at the 'ctr(aes)' implementation in there a few
> > days ago (I think I was trying to debug this very issue, but for some
> > reason I only looked at ctr(aes)...) and I didn't find any bug, so
> > that's why I jumped to suspecting the algif_skcipher code... I should
> > have double-checked :)
> >
> > It turns out the 'cbc(aes)' (and actually also 'xts(aes)')
> > implementation is coded a bit differently and they both *do* contain
> > the sleep-in-atomic bug. I will try to fix them according to the
> > correct CTR implementation and send a patch.
>
> CC: linuxppc-dev@lists.ozlabs.org <linuxppc-dev@lists.ozlabs.org>
>
> >
> > Thanks,
> > Ondrej
> >
> > > @Marcelo: shouldn't be the sleep flag be cleared when entering the
> > > preempt_disable section?
> > >
> > > Ciao
> > > Stephan
> > >
> > >
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^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH] crypto: vmx - Fix sleep-in-atomic bugs
[not found] ` <CAAUqJDt_y04ts7Aq0U0fhXYRus2ckkEohBTkga0pjqfoQaBOCA@mail.gmail.com>
2018-08-21 15:03 ` Christophe LEROY
@ 2018-08-21 15:16 ` Ondrej Mosnacek
2018-08-21 15:24 ` Ondrej Mosnáček
2018-08-22 6:26 ` [PATCH v2] " Ondrej Mosnacek
2 siblings, 1 reply; 17+ messages in thread
From: Ondrej Mosnacek @ 2018-08-21 15:16 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-crypto, Stephan Mueller, Benjamin Herrenschmidt,
Paul Mackerras, Michael Ellerman, Marcelo Henrique Cerri,
Leonidas S . Barbosa, Ondrej Mosnacek, stable
This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
implementations. The problem is that the blkcipher_* functions should
not be called in atomic context.
The bugs can be reproduced via the AF_ALG interface by trying to
encrypt/decrypt sufficiently large buffers (at least 64 KiB) using the
VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
trigger BUG in crypto_yield():
[ 891.863680] BUG: sleeping function called from invalid context at include/crypto/algapi.h:424
[ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name: kcapi-enc
[ 891.864739] 1 lock held by kcapi-enc/12347:
[ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at: skcipher_recvmsg+0x50/0x530
[ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted 4.19.0-0.rc0.git3.1.fc30.ppc64le #1
[ 891.865251] Call Trace:
[ 891.865340] [c0000003387578c0] [c000000000d67ea4] dump_stack+0xe8/0x164 (unreliable)
[ 891.865511] [c000000338757910] [c000000000172a58] ___might_sleep+0x2f8/0x310
[ 891.865679] [c000000338757990] [c0000000006bff74] blkcipher_walk_done+0x374/0x4a0
[ 891.865825] [c0000003387579e0] [d000000007e73e70] p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto]
[ 891.865993] [c000000338757ad0] [c0000000006c0ee0] skcipher_encrypt_blkcipher+0x60/0x80
[ 891.866128] [c000000338757b10] [c0000000006ec504] skcipher_recvmsg+0x424/0x530
[ 891.866283] [c000000338757bd0] [c000000000b00654] sock_recvmsg+0x74/0xa0
[ 891.866403] [c000000338757c10] [c000000000b00f64] ___sys_recvmsg+0xf4/0x2f0
[ 891.866515] [c000000338757d90] [c000000000b02bb8] __sys_recvmsg+0x68/0xe0
[ 891.866631] [c000000338757e30] [c00000000000bbe4] system_call+0x5c/0x70
Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX module")
Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
Cc: stable@vger.kernel.org
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
---
This patch should fix the issue, but I didn't test it. (I'll see if I
can find some time tomorrow to try and recompile the kernel on a PPC
machine... in the meantime please review :)
drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
drivers/crypto/vmx/aes_xts.c | 19 ++++++++++++-------
2 files changed, 26 insertions(+), 23 deletions(-)
diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
index 5285ece4f33a..b71895871be3 100644
--- a/drivers/crypto/vmx/aes_cbc.c
+++ b/drivers/crypto/vmx/aes_cbc.c
@@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
ret = crypto_skcipher_encrypt(req);
skcipher_request_zero(req);
} else {
- preempt_disable();
- pagefault_disable();
- enable_kernel_vsx();
-
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
+ preempt_disable();
+ pagefault_disable();
+ enable_kernel_vsx();
aes_p8_cbc_encrypt(walk.src.virt.addr,
walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK,
&ctx->enc_key, walk.iv, 1);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
+
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
-
- disable_kernel_vsx();
- pagefault_enable();
- preempt_enable();
}
return ret;
@@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
ret = crypto_skcipher_decrypt(req);
skcipher_request_zero(req);
} else {
- preempt_disable();
- pagefault_disable();
- enable_kernel_vsx();
-
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
+ preempt_disable();
+ pagefault_disable();
+ enable_kernel_vsx();
aes_p8_cbc_encrypt(walk.src.virt.addr,
walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK,
&ctx->dec_key, walk.iv, 0);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
+
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
-
- disable_kernel_vsx();
- pagefault_enable();
- preempt_enable();
}
return ret;
diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c
index 8bd9aff0f55f..016ef52390c9 100644
--- a/drivers/crypto/vmx/aes_xts.c
+++ b/drivers/crypto/vmx/aes_xts.c
@@ -116,13 +116,14 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
ret = enc? crypto_skcipher_encrypt(req) : crypto_skcipher_decrypt(req);
skcipher_request_zero(req);
} else {
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+
+ ret = blkcipher_walk_virt(desc, &walk);
+
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
- blkcipher_walk_init(&walk, dst, src, nbytes);
-
- ret = blkcipher_walk_virt(desc, &walk);
iv = walk.iv;
memset(tweak, 0, AES_BLOCK_SIZE);
aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
@@ -135,13 +136,17 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
+
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
- }
- disable_kernel_vsx();
- pagefault_enable();
- preempt_enable();
+ preempt_disable();
+ pagefault_disable();
+ enable_kernel_vsx();
+ }
}
return ret;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 17+ messages in thread
* Re: [PATCH] crypto: vmx - Fix sleep-in-atomic bugs
2018-08-21 15:16 ` [PATCH] crypto: vmx - Fix sleep-in-atomic bugs Ondrej Mosnacek
@ 2018-08-21 15:24 ` Ondrej Mosnáček
0 siblings, 0 replies; 17+ messages in thread
From: Ondrej Mosnáček @ 2018-08-21 15:24 UTC (permalink / raw)
To: omosnace
Cc: Herbert Xu, linux-crypto, Stephan Mueller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
marcelo.cerri, leo.barbosa, stable, Paulo Flabiano Smorigo,
linuxppc-dev
CC: Paulo Flabiano Smorigo <pfsmorigo@linux.vnet.ibm.com>,
linuxppc-dev@lists.ozlabs.org
(Sorry, sent this before reading new e-mails in the thread...)
ut 21. 8. 2018 o 17:18 Ondrej Mosnacek <omosnace@redhat.com> napísal(a):
>
> This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
> implementations. The problem is that the blkcipher_* functions should
> not be called in atomic context.
>
> The bugs can be reproduced via the AF_ALG interface by trying to
> encrypt/decrypt sufficiently large buffers (at least 64 KiB) using the
> VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
> trigger BUG in crypto_yield():
>
> [ 891.863680] BUG: sleeping function called from invalid context at include/crypto/algapi.h:424
> [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name: kcapi-enc
> [ 891.864739] 1 lock held by kcapi-enc/12347:
> [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at: skcipher_recvmsg+0x50/0x530
> [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted 4.19.0-0.rc0.git3.1.fc30.ppc64le #1
> [ 891.865251] Call Trace:
> [ 891.865340] [c0000003387578c0] [c000000000d67ea4] dump_stack+0xe8/0x164 (unreliable)
> [ 891.865511] [c000000338757910] [c000000000172a58] ___might_sleep+0x2f8/0x310
> [ 891.865679] [c000000338757990] [c0000000006bff74] blkcipher_walk_done+0x374/0x4a0
> [ 891.865825] [c0000003387579e0] [d000000007e73e70] p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto]
> [ 891.865993] [c000000338757ad0] [c0000000006c0ee0] skcipher_encrypt_blkcipher+0x60/0x80
> [ 891.866128] [c000000338757b10] [c0000000006ec504] skcipher_recvmsg+0x424/0x530
> [ 891.866283] [c000000338757bd0] [c000000000b00654] sock_recvmsg+0x74/0xa0
> [ 891.866403] [c000000338757c10] [c000000000b00f64] ___sys_recvmsg+0xf4/0x2f0
> [ 891.866515] [c000000338757d90] [c000000000b02bb8] __sys_recvmsg+0x68/0xe0
> [ 891.866631] [c000000338757e30] [c00000000000bbe4] system_call+0x5c/0x70
>
> Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX module")
> Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
> Cc: stable@vger.kernel.org
> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> ---
> This patch should fix the issue, but I didn't test it. (I'll see if I
> can find some time tomorrow to try and recompile the kernel on a PPC
> machine... in the meantime please review :)
>
> drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
> drivers/crypto/vmx/aes_xts.c | 19 ++++++++++++-------
> 2 files changed, 26 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
> index 5285ece4f33a..b71895871be3 100644
> --- a/drivers/crypto/vmx/aes_cbc.c
> +++ b/drivers/crypto/vmx/aes_cbc.c
> @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
> ret = crypto_skcipher_encrypt(req);
> skcipher_request_zero(req);
> } else {
> - preempt_disable();
> - pagefault_disable();
> - enable_kernel_vsx();
> -
> blkcipher_walk_init(&walk, dst, src, nbytes);
> ret = blkcipher_walk_virt(desc, &walk);
> while ((nbytes = walk.nbytes)) {
> + preempt_disable();
> + pagefault_disable();
> + enable_kernel_vsx();
> aes_p8_cbc_encrypt(walk.src.virt.addr,
> walk.dst.virt.addr,
> nbytes & AES_BLOCK_MASK,
> &ctx->enc_key, walk.iv, 1);
> + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
> +
> nbytes &= AES_BLOCK_SIZE - 1;
> ret = blkcipher_walk_done(desc, &walk, nbytes);
> }
> -
> - disable_kernel_vsx();
> - pagefault_enable();
> - preempt_enable();
> }
>
> return ret;
> @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
> ret = crypto_skcipher_decrypt(req);
> skcipher_request_zero(req);
> } else {
> - preempt_disable();
> - pagefault_disable();
> - enable_kernel_vsx();
> -
> blkcipher_walk_init(&walk, dst, src, nbytes);
> ret = blkcipher_walk_virt(desc, &walk);
> while ((nbytes = walk.nbytes)) {
> + preempt_disable();
> + pagefault_disable();
> + enable_kernel_vsx();
> aes_p8_cbc_encrypt(walk.src.virt.addr,
> walk.dst.virt.addr,
> nbytes & AES_BLOCK_MASK,
> &ctx->dec_key, walk.iv, 0);
> + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
> +
> nbytes &= AES_BLOCK_SIZE - 1;
> ret = blkcipher_walk_done(desc, &walk, nbytes);
> }
> -
> - disable_kernel_vsx();
> - pagefault_enable();
> - preempt_enable();
> }
>
> return ret;
> diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c
> index 8bd9aff0f55f..016ef52390c9 100644
> --- a/drivers/crypto/vmx/aes_xts.c
> +++ b/drivers/crypto/vmx/aes_xts.c
> @@ -116,13 +116,14 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
> ret = enc? crypto_skcipher_encrypt(req) : crypto_skcipher_decrypt(req);
> skcipher_request_zero(req);
> } else {
> + blkcipher_walk_init(&walk, dst, src, nbytes);
> +
> + ret = blkcipher_walk_virt(desc, &walk);
> +
> preempt_disable();
> pagefault_disable();
> enable_kernel_vsx();
>
> - blkcipher_walk_init(&walk, dst, src, nbytes);
> -
> - ret = blkcipher_walk_virt(desc, &walk);
> iv = walk.iv;
> memset(tweak, 0, AES_BLOCK_SIZE);
> aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
> @@ -135,13 +136,17 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
> aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
> nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
>
> + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
> +
> nbytes &= AES_BLOCK_SIZE - 1;
> ret = blkcipher_walk_done(desc, &walk, nbytes);
> - }
>
> - disable_kernel_vsx();
> - pagefault_enable();
> - preempt_enable();
> + preempt_disable();
> + pagefault_disable();
> + enable_kernel_vsx();
> + }
> }
> return ret;
> }
> --
> 2.17.1
>
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH] crypto: vmx - Fix sleep-in-atomic bugs
@ 2018-08-21 15:24 ` Ondrej Mosnáček
0 siblings, 0 replies; 17+ messages in thread
From: Ondrej Mosnáček @ 2018-08-21 15:24 UTC (permalink / raw)
To: omosnace
Cc: Herbert Xu, linux-crypto, Stephan Mueller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
marcelo.cerri, leo.barbosa, stable, Paulo Flabiano Smorigo,
linuxppc-dev
CC: Paulo Flabiano Smorigo <pfsmorigo@linux.vnet.ibm.com>,
linuxppc-dev@lists.ozlabs.org
(Sorry, sent this before reading new e-mails in the thread...)
ut 21. 8. 2018 o 17:18 Ondrej Mosnacek <omosnace@redhat.com> nap=C3=ADsal(a=
):
>
> This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
> implementations. The problem is that the blkcipher_* functions should
> not be called in atomic context.
>
> The bugs can be reproduced via the AF_ALG interface by trying to
> encrypt/decrypt sufficiently large buffers (at least 64 KiB) using the
> VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
> trigger BUG in crypto_yield():
>
> [ 891.863680] BUG: sleeping function called from invalid context at incl=
ude/crypto/algapi.h:424
> [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name: kcap=
i-enc
> [ 891.864739] 1 lock held by kcapi-enc/12347:
> [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at: skcipher=
_recvmsg+0x50/0x530
> [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted 4.19.0-0.rc0=
.git3.1.fc30.ppc64le #1
> [ 891.865251] Call Trace:
> [ 891.865340] [c0000003387578c0] [c000000000d67ea4] dump_stack+0xe8/0x16=
4 (unreliable)
> [ 891.865511] [c000000338757910] [c000000000172a58] ___might_sleep+0x2f8=
/0x310
> [ 891.865679] [c000000338757990] [c0000000006bff74] blkcipher_walk_done+=
0x374/0x4a0
> [ 891.865825] [c0000003387579e0] [d000000007e73e70] p8_aes_cbc_encrypt+0=
x1c8/0x260 [vmx_crypto]
> [ 891.865993] [c000000338757ad0] [c0000000006c0ee0] skcipher_encrypt_blk=
cipher+0x60/0x80
> [ 891.866128] [c000000338757b10] [c0000000006ec504] skcipher_recvmsg+0x4=
24/0x530
> [ 891.866283] [c000000338757bd0] [c000000000b00654] sock_recvmsg+0x74/0x=
a0
> [ 891.866403] [c000000338757c10] [c000000000b00f64] ___sys_recvmsg+0xf4/=
0x2f0
> [ 891.866515] [c000000338757d90] [c000000000b02bb8] __sys_recvmsg+0x68/0=
xe0
> [ 891.866631] [c000000338757e30] [c00000000000bbe4] system_call+0x5c/0x7=
0
>
> Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX module")
> Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
> Cc: stable@vger.kernel.org
> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> ---
> This patch should fix the issue, but I didn't test it. (I'll see if I
> can find some time tomorrow to try and recompile the kernel on a PPC
> machine... in the meantime please review :)
>
> drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
> drivers/crypto/vmx/aes_xts.c | 19 ++++++++++++-------
> 2 files changed, 26 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
> index 5285ece4f33a..b71895871be3 100644
> --- a/drivers/crypto/vmx/aes_cbc.c
> +++ b/drivers/crypto/vmx/aes_cbc.c
> @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc=
*desc,
> ret =3D crypto_skcipher_encrypt(req);
> skcipher_request_zero(req);
> } else {
> - preempt_disable();
> - pagefault_disable();
> - enable_kernel_vsx();
> -
> blkcipher_walk_init(&walk, dst, src, nbytes);
> ret =3D blkcipher_walk_virt(desc, &walk);
> while ((nbytes =3D walk.nbytes)) {
> + preempt_disable();
> + pagefault_disable();
> + enable_kernel_vsx();
> aes_p8_cbc_encrypt(walk.src.virt.addr,
> walk.dst.virt.addr,
> nbytes & AES_BLOCK_MASK,
> &ctx->enc_key, walk.iv, 1);
> + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
> +
> nbytes &=3D AES_BLOCK_SIZE - 1;
> ret =3D blkcipher_walk_done(desc, &walk, nbytes);
> }
> -
> - disable_kernel_vsx();
> - pagefault_enable();
> - preempt_enable();
> }
>
> return ret;
> @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc=
*desc,
> ret =3D crypto_skcipher_decrypt(req);
> skcipher_request_zero(req);
> } else {
> - preempt_disable();
> - pagefault_disable();
> - enable_kernel_vsx();
> -
> blkcipher_walk_init(&walk, dst, src, nbytes);
> ret =3D blkcipher_walk_virt(desc, &walk);
> while ((nbytes =3D walk.nbytes)) {
> + preempt_disable();
> + pagefault_disable();
> + enable_kernel_vsx();
> aes_p8_cbc_encrypt(walk.src.virt.addr,
> walk.dst.virt.addr,
> nbytes & AES_BLOCK_MASK,
> &ctx->dec_key, walk.iv, 0);
> + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
> +
> nbytes &=3D AES_BLOCK_SIZE - 1;
> ret =3D blkcipher_walk_done(desc, &walk, nbytes);
> }
> -
> - disable_kernel_vsx();
> - pagefault_enable();
> - preempt_enable();
> }
>
> return ret;
> diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c
> index 8bd9aff0f55f..016ef52390c9 100644
> --- a/drivers/crypto/vmx/aes_xts.c
> +++ b/drivers/crypto/vmx/aes_xts.c
> @@ -116,13 +116,14 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *=
desc,
> ret =3D enc? crypto_skcipher_encrypt(req) : crypto_skciph=
er_decrypt(req);
> skcipher_request_zero(req);
> } else {
> + blkcipher_walk_init(&walk, dst, src, nbytes);
> +
> + ret =3D blkcipher_walk_virt(desc, &walk);
> +
> preempt_disable();
> pagefault_disable();
> enable_kernel_vsx();
>
> - blkcipher_walk_init(&walk, dst, src, nbytes);
> -
> - ret =3D blkcipher_walk_virt(desc, &walk);
> iv =3D walk.iv;
> memset(tweak, 0, AES_BLOCK_SIZE);
> aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
> @@ -135,13 +136,17 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *=
desc,
> aes_p8_xts_decrypt(walk.src.virt.addr, wa=
lk.dst.virt.addr,
> nbytes & AES_BLOCK_MASK, =
&ctx->dec_key, NULL, tweak);
>
> + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
> +
> nbytes &=3D AES_BLOCK_SIZE - 1;
> ret =3D blkcipher_walk_done(desc, &walk, nbytes);
> - }
>
> - disable_kernel_vsx();
> - pagefault_enable();
> - preempt_enable();
> + preempt_disable();
> + pagefault_disable();
> + enable_kernel_vsx();
> + }
> }
> return ret;
> }
> --
> 2.17.1
>
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH] crypto: vmx - Fix sleep-in-atomic bugs
2018-08-21 15:24 ` Ondrej Mosnáček
@ 2018-08-21 16:41 ` Marcelo Henrique Cerri
-1 siblings, 0 replies; 17+ messages in thread
From: Marcelo Henrique Cerri @ 2018-08-21 16:41 UTC (permalink / raw)
To: Ondrej Mosnáček
Cc: omosnace, Herbert Xu, linux-crypto, Stephan Mueller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
leo.barbosa, stable, Paulo Flabiano Smorigo, linuxppc-dev
[-- Attachment #1: Type: text/plain, Size: 7943 bytes --]
On Tue, Aug 21, 2018 at 05:24:45PM +0200, Ondrej Mosnáček wrote:
> CC: Paulo Flabiano Smorigo <pfsmorigo@linux.vnet.ibm.com>,
> linuxppc-dev@lists.ozlabs.org
>
> (Sorry, sent this before reading new e-mails in the thread...)
>
> ut 21. 8. 2018 o 17:18 Ondrej Mosnacek <omosnace@redhat.com> napísal(a):
> >
> > This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
> > implementations. The problem is that the blkcipher_* functions should
> > not be called in atomic context.
> >
> > The bugs can be reproduced via the AF_ALG interface by trying to
> > encrypt/decrypt sufficiently large buffers (at least 64 KiB) using the
> > VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
> > trigger BUG in crypto_yield():
> >
> > [ 891.863680] BUG: sleeping function called from invalid context at include/crypto/algapi.h:424
> > [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name: kcapi-enc
> > [ 891.864739] 1 lock held by kcapi-enc/12347:
> > [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at: skcipher_recvmsg+0x50/0x530
> > [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted 4.19.0-0.rc0.git3.1.fc30.ppc64le #1
> > [ 891.865251] Call Trace:
> > [ 891.865340] [c0000003387578c0] [c000000000d67ea4] dump_stack+0xe8/0x164 (unreliable)
> > [ 891.865511] [c000000338757910] [c000000000172a58] ___might_sleep+0x2f8/0x310
> > [ 891.865679] [c000000338757990] [c0000000006bff74] blkcipher_walk_done+0x374/0x4a0
> > [ 891.865825] [c0000003387579e0] [d000000007e73e70] p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto]
> > [ 891.865993] [c000000338757ad0] [c0000000006c0ee0] skcipher_encrypt_blkcipher+0x60/0x80
> > [ 891.866128] [c000000338757b10] [c0000000006ec504] skcipher_recvmsg+0x424/0x530
> > [ 891.866283] [c000000338757bd0] [c000000000b00654] sock_recvmsg+0x74/0xa0
> > [ 891.866403] [c000000338757c10] [c000000000b00f64] ___sys_recvmsg+0xf4/0x2f0
> > [ 891.866515] [c000000338757d90] [c000000000b02bb8] __sys_recvmsg+0x68/0xe0
> > [ 891.866631] [c000000338757e30] [c00000000000bbe4] system_call+0x5c/0x70
> >
> > Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX module")
> > Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> > ---
> > This patch should fix the issue, but I didn't test it. (I'll see if I
> > can find some time tomorrow to try and recompile the kernel on a PPC
> > machine... in the meantime please review :)
> >
> > drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
> > drivers/crypto/vmx/aes_xts.c | 19 ++++++++++++-------
> > 2 files changed, 26 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
> > index 5285ece4f33a..b71895871be3 100644
> > --- a/drivers/crypto/vmx/aes_cbc.c
> > +++ b/drivers/crypto/vmx/aes_cbc.c
> > @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
> > ret = crypto_skcipher_encrypt(req);
> > skcipher_request_zero(req);
> > } else {
> > - preempt_disable();
> > - pagefault_disable();
> > - enable_kernel_vsx();
> > -
> > blkcipher_walk_init(&walk, dst, src, nbytes);
> > ret = blkcipher_walk_virt(desc, &walk);
> > while ((nbytes = walk.nbytes)) {
> > + preempt_disable();
> > + pagefault_disable();
> > + enable_kernel_vsx();
> > aes_p8_cbc_encrypt(walk.src.virt.addr,
> > walk.dst.virt.addr,
> > nbytes & AES_BLOCK_MASK,
> > &ctx->enc_key, walk.iv, 1);
> > + disable_kernel_vsx();
> > + pagefault_enable();
> > + preempt_enable();
> > +
> > nbytes &= AES_BLOCK_SIZE - 1;
> > ret = blkcipher_walk_done(desc, &walk, nbytes);
> > }
> > -
> > - disable_kernel_vsx();
> > - pagefault_enable();
> > - preempt_enable();
> > }
> >
> > return ret;
> > @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
> > ret = crypto_skcipher_decrypt(req);
> > skcipher_request_zero(req);
> > } else {
> > - preempt_disable();
> > - pagefault_disable();
> > - enable_kernel_vsx();
> > -
> > blkcipher_walk_init(&walk, dst, src, nbytes);
> > ret = blkcipher_walk_virt(desc, &walk);
> > while ((nbytes = walk.nbytes)) {
> > + preempt_disable();
> > + pagefault_disable();
> > + enable_kernel_vsx();
> > aes_p8_cbc_encrypt(walk.src.virt.addr,
> > walk.dst.virt.addr,
> > nbytes & AES_BLOCK_MASK,
> > &ctx->dec_key, walk.iv, 0);
> > + disable_kernel_vsx();
> > + pagefault_enable();
> > + preempt_enable();
> > +
> > nbytes &= AES_BLOCK_SIZE - 1;
> > ret = blkcipher_walk_done(desc, &walk, nbytes);
> > }
> > -
> > - disable_kernel_vsx();
> > - pagefault_enable();
> > - preempt_enable();
> > }
> >
> > return ret;
> > diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c
> > index 8bd9aff0f55f..016ef52390c9 100644
> > --- a/drivers/crypto/vmx/aes_xts.c
> > +++ b/drivers/crypto/vmx/aes_xts.c
> > @@ -116,13 +116,14 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
> > ret = enc? crypto_skcipher_encrypt(req) : crypto_skcipher_decrypt(req);
> > skcipher_request_zero(req);
> > } else {
> > + blkcipher_walk_init(&walk, dst, src, nbytes);
> > +
> > + ret = blkcipher_walk_virt(desc, &walk);
> > +
> > preempt_disable();
> > pagefault_disable();
> > enable_kernel_vsx();
> >
> > - blkcipher_walk_init(&walk, dst, src, nbytes);
> > -
> > - ret = blkcipher_walk_virt(desc, &walk);
> > iv = walk.iv;
> > memset(tweak, 0, AES_BLOCK_SIZE);
> > aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
> > @@ -135,13 +136,17 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
> > aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
> > nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
> >
> > + disable_kernel_vsx();
> > + pagefault_enable();
> > + preempt_enable();
> > +
> > nbytes &= AES_BLOCK_SIZE - 1;
> > ret = blkcipher_walk_done(desc, &walk, nbytes);
> > - }
> >
> > - disable_kernel_vsx();
> > - pagefault_enable();
> > - preempt_enable();
> > + preempt_disable();
> > + pagefault_disable();
> > + enable_kernel_vsx();
> > + }
That doesn't seem right. It would leave preemption disabled when
leaving the function.
> > }
> > return ret;
> > }
> > --
> > 2.17.1
> >
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH] crypto: vmx - Fix sleep-in-atomic bugs
@ 2018-08-21 16:41 ` Marcelo Henrique Cerri
0 siblings, 0 replies; 17+ messages in thread
From: Marcelo Henrique Cerri @ 2018-08-21 16:41 UTC (permalink / raw)
To: Ondrej Mosnáček
Cc: omosnace, Herbert Xu, linux-crypto, Stephan Mueller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
leo.barbosa, stable, Paulo Flabiano Smorigo, linuxppc-dev
[-- Attachment #1: Type: text/plain, Size: 7970 bytes --]
On Tue, Aug 21, 2018 at 05:24:45PM +0200, Ondrej Mosnáček wrote:
> CC: Paulo Flabiano Smorigo <pfsmorigo@linux.vnet.ibm.com>,
> linuxppc-dev@lists.ozlabs.org
>
> (Sorry, sent this before reading new e-mails in the thread...)
>
> ut 21. 8. 2018 o 17:18 Ondrej Mosnacek <omosnace@redhat.com> napísal(a):
> >
> > This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
> > implementations. The problem is that the blkcipher_* functions should
> > not be called in atomic context.
> >
> > The bugs can be reproduced via the AF_ALG interface by trying to
> > encrypt/decrypt sufficiently large buffers (at least 64 KiB) using the
> > VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
> > trigger BUG in crypto_yield():
> >
> > [ 891.863680] BUG: sleeping function called from invalid context at include/crypto/algapi.h:424
> > [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name: kcapi-enc
> > [ 891.864739] 1 lock held by kcapi-enc/12347:
> > [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at: skcipher_recvmsg+0x50/0x530
> > [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted 4.19.0-0.rc0.git3.1.fc30.ppc64le #1
> > [ 891.865251] Call Trace:
> > [ 891.865340] [c0000003387578c0] [c000000000d67ea4] dump_stack+0xe8/0x164 (unreliable)
> > [ 891.865511] [c000000338757910] [c000000000172a58] ___might_sleep+0x2f8/0x310
> > [ 891.865679] [c000000338757990] [c0000000006bff74] blkcipher_walk_done+0x374/0x4a0
> > [ 891.865825] [c0000003387579e0] [d000000007e73e70] p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto]
> > [ 891.865993] [c000000338757ad0] [c0000000006c0ee0] skcipher_encrypt_blkcipher+0x60/0x80
> > [ 891.866128] [c000000338757b10] [c0000000006ec504] skcipher_recvmsg+0x424/0x530
> > [ 891.866283] [c000000338757bd0] [c000000000b00654] sock_recvmsg+0x74/0xa0
> > [ 891.866403] [c000000338757c10] [c000000000b00f64] ___sys_recvmsg+0xf4/0x2f0
> > [ 891.866515] [c000000338757d90] [c000000000b02bb8] __sys_recvmsg+0x68/0xe0
> > [ 891.866631] [c000000338757e30] [c00000000000bbe4] system_call+0x5c/0x70
> >
> > Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX module")
> > Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> > ---
> > This patch should fix the issue, but I didn't test it. (I'll see if I
> > can find some time tomorrow to try and recompile the kernel on a PPC
> > machine... in the meantime please review :)
> >
> > drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
> > drivers/crypto/vmx/aes_xts.c | 19 ++++++++++++-------
> > 2 files changed, 26 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
> > index 5285ece4f33a..b71895871be3 100644
> > --- a/drivers/crypto/vmx/aes_cbc.c
> > +++ b/drivers/crypto/vmx/aes_cbc.c
> > @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
> > ret = crypto_skcipher_encrypt(req);
> > skcipher_request_zero(req);
> > } else {
> > - preempt_disable();
> > - pagefault_disable();
> > - enable_kernel_vsx();
> > -
> > blkcipher_walk_init(&walk, dst, src, nbytes);
> > ret = blkcipher_walk_virt(desc, &walk);
> > while ((nbytes = walk.nbytes)) {
> > + preempt_disable();
> > + pagefault_disable();
> > + enable_kernel_vsx();
> > aes_p8_cbc_encrypt(walk.src.virt.addr,
> > walk.dst.virt.addr,
> > nbytes & AES_BLOCK_MASK,
> > &ctx->enc_key, walk.iv, 1);
> > + disable_kernel_vsx();
> > + pagefault_enable();
> > + preempt_enable();
> > +
> > nbytes &= AES_BLOCK_SIZE - 1;
> > ret = blkcipher_walk_done(desc, &walk, nbytes);
> > }
> > -
> > - disable_kernel_vsx();
> > - pagefault_enable();
> > - preempt_enable();
> > }
> >
> > return ret;
> > @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
> > ret = crypto_skcipher_decrypt(req);
> > skcipher_request_zero(req);
> > } else {
> > - preempt_disable();
> > - pagefault_disable();
> > - enable_kernel_vsx();
> > -
> > blkcipher_walk_init(&walk, dst, src, nbytes);
> > ret = blkcipher_walk_virt(desc, &walk);
> > while ((nbytes = walk.nbytes)) {
> > + preempt_disable();
> > + pagefault_disable();
> > + enable_kernel_vsx();
> > aes_p8_cbc_encrypt(walk.src.virt.addr,
> > walk.dst.virt.addr,
> > nbytes & AES_BLOCK_MASK,
> > &ctx->dec_key, walk.iv, 0);
> > + disable_kernel_vsx();
> > + pagefault_enable();
> > + preempt_enable();
> > +
> > nbytes &= AES_BLOCK_SIZE - 1;
> > ret = blkcipher_walk_done(desc, &walk, nbytes);
> > }
> > -
> > - disable_kernel_vsx();
> > - pagefault_enable();
> > - preempt_enable();
> > }
> >
> > return ret;
> > diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c
> > index 8bd9aff0f55f..016ef52390c9 100644
> > --- a/drivers/crypto/vmx/aes_xts.c
> > +++ b/drivers/crypto/vmx/aes_xts.c
> > @@ -116,13 +116,14 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
> > ret = enc? crypto_skcipher_encrypt(req) : crypto_skcipher_decrypt(req);
> > skcipher_request_zero(req);
> > } else {
> > + blkcipher_walk_init(&walk, dst, src, nbytes);
> > +
> > + ret = blkcipher_walk_virt(desc, &walk);
> > +
> > preempt_disable();
> > pagefault_disable();
> > enable_kernel_vsx();
> >
> > - blkcipher_walk_init(&walk, dst, src, nbytes);
> > -
> > - ret = blkcipher_walk_virt(desc, &walk);
> > iv = walk.iv;
> > memset(tweak, 0, AES_BLOCK_SIZE);
> > aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
> > @@ -135,13 +136,17 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
> > aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
> > nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
> >
> > + disable_kernel_vsx();
> > + pagefault_enable();
> > + preempt_enable();
> > +
> > nbytes &= AES_BLOCK_SIZE - 1;
> > ret = blkcipher_walk_done(desc, &walk, nbytes);
> > - }
> >
> > - disable_kernel_vsx();
> > - pagefault_enable();
> > - preempt_enable();
> > + preempt_disable();
> > + pagefault_disable();
> > + enable_kernel_vsx();
> > + }
That doesn't seem right. It would leave preemption disabled when
leaving the function.
> > }
> > return ret;
> > }
> > --
> > 2.17.1
> >
--
Regards,
Marcelo
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH] crypto: vmx - Fix sleep-in-atomic bugs
2018-08-21 16:41 ` Marcelo Henrique Cerri
@ 2018-08-22 6:05 ` Ondrej Mosnáček
-1 siblings, 0 replies; 17+ messages in thread
From: Ondrej Mosnáček @ 2018-08-22 6:05 UTC (permalink / raw)
To: marcelo.cerri
Cc: omosnace, Herbert Xu, linux-crypto, Stephan Mueller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
leo.barbosa, stable, Paulo Flabiano Smorigo, linuxppc-dev
ut 21. 8. 2018 o 18:41 Marcelo Henrique Cerri
<marcelo.cerri@canonical.com> napísal(a):
> On Tue, Aug 21, 2018 at 05:24:45PM +0200, Ondrej Mosnáček wrote:
> > CC: Paulo Flabiano Smorigo <pfsmorigo@linux.vnet.ibm.com>,
> > linuxppc-dev@lists.ozlabs.org
> >
> > (Sorry, sent this before reading new e-mails in the thread...)
> >
> > ut 21. 8. 2018 o 17:18 Ondrej Mosnacek <omosnace@redhat.com> napísal(a):
> > >
> > > This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
> > > implementations. The problem is that the blkcipher_* functions should
> > > not be called in atomic context.
> > >
> > > The bugs can be reproduced via the AF_ALG interface by trying to
> > > encrypt/decrypt sufficiently large buffers (at least 64 KiB) using the
> > > VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
> > > trigger BUG in crypto_yield():
> > >
> > > [ 891.863680] BUG: sleeping function called from invalid context at include/crypto/algapi.h:424
> > > [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name: kcapi-enc
> > > [ 891.864739] 1 lock held by kcapi-enc/12347:
> > > [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at: skcipher_recvmsg+0x50/0x530
> > > [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted 4.19.0-0.rc0.git3.1.fc30.ppc64le #1
> > > [ 891.865251] Call Trace:
> > > [ 891.865340] [c0000003387578c0] [c000000000d67ea4] dump_stack+0xe8/0x164 (unreliable)
> > > [ 891.865511] [c000000338757910] [c000000000172a58] ___might_sleep+0x2f8/0x310
> > > [ 891.865679] [c000000338757990] [c0000000006bff74] blkcipher_walk_done+0x374/0x4a0
> > > [ 891.865825] [c0000003387579e0] [d000000007e73e70] p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto]
> > > [ 891.865993] [c000000338757ad0] [c0000000006c0ee0] skcipher_encrypt_blkcipher+0x60/0x80
> > > [ 891.866128] [c000000338757b10] [c0000000006ec504] skcipher_recvmsg+0x424/0x530
> > > [ 891.866283] [c000000338757bd0] [c000000000b00654] sock_recvmsg+0x74/0xa0
> > > [ 891.866403] [c000000338757c10] [c000000000b00f64] ___sys_recvmsg+0xf4/0x2f0
> > > [ 891.866515] [c000000338757d90] [c000000000b02bb8] __sys_recvmsg+0x68/0xe0
> > > [ 891.866631] [c000000338757e30] [c00000000000bbe4] system_call+0x5c/0x70
> > >
> > > Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX module")
> > > Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
> > > Cc: stable@vger.kernel.org
> > > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> > > ---
> > > This patch should fix the issue, but I didn't test it. (I'll see if I
> > > can find some time tomorrow to try and recompile the kernel on a PPC
> > > machine... in the meantime please review :)
> > >
> > > drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
> > > drivers/crypto/vmx/aes_xts.c | 19 ++++++++++++-------
> > > 2 files changed, 26 insertions(+), 23 deletions(-)
> > >
> > > diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
> > > index 5285ece4f33a..b71895871be3 100644
> > > --- a/drivers/crypto/vmx/aes_cbc.c
> > > +++ b/drivers/crypto/vmx/aes_cbc.c
> > > @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
> > > ret = crypto_skcipher_encrypt(req);
> > > skcipher_request_zero(req);
> > > } else {
> > > - preempt_disable();
> > > - pagefault_disable();
> > > - enable_kernel_vsx();
> > > -
> > > blkcipher_walk_init(&walk, dst, src, nbytes);
> > > ret = blkcipher_walk_virt(desc, &walk);
> > > while ((nbytes = walk.nbytes)) {
> > > + preempt_disable();
> > > + pagefault_disable();
> > > + enable_kernel_vsx();
> > > aes_p8_cbc_encrypt(walk.src.virt.addr,
> > > walk.dst.virt.addr,
> > > nbytes & AES_BLOCK_MASK,
> > > &ctx->enc_key, walk.iv, 1);
> > > + disable_kernel_vsx();
> > > + pagefault_enable();
> > > + preempt_enable();
> > > +
> > > nbytes &= AES_BLOCK_SIZE - 1;
> > > ret = blkcipher_walk_done(desc, &walk, nbytes);
> > > }
> > > -
> > > - disable_kernel_vsx();
> > > - pagefault_enable();
> > > - preempt_enable();
> > > }
> > >
> > > return ret;
> > > @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
> > > ret = crypto_skcipher_decrypt(req);
> > > skcipher_request_zero(req);
> > > } else {
> > > - preempt_disable();
> > > - pagefault_disable();
> > > - enable_kernel_vsx();
> > > -
> > > blkcipher_walk_init(&walk, dst, src, nbytes);
> > > ret = blkcipher_walk_virt(desc, &walk);
> > > while ((nbytes = walk.nbytes)) {
> > > + preempt_disable();
> > > + pagefault_disable();
> > > + enable_kernel_vsx();
> > > aes_p8_cbc_encrypt(walk.src.virt.addr,
> > > walk.dst.virt.addr,
> > > nbytes & AES_BLOCK_MASK,
> > > &ctx->dec_key, walk.iv, 0);
> > > + disable_kernel_vsx();
> > > + pagefault_enable();
> > > + preempt_enable();
> > > +
> > > nbytes &= AES_BLOCK_SIZE - 1;
> > > ret = blkcipher_walk_done(desc, &walk, nbytes);
> > > }
> > > -
> > > - disable_kernel_vsx();
> > > - pagefault_enable();
> > > - preempt_enable();
> > > }
> > >
> > > return ret;
> > > diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c
> > > index 8bd9aff0f55f..016ef52390c9 100644
> > > --- a/drivers/crypto/vmx/aes_xts.c
> > > +++ b/drivers/crypto/vmx/aes_xts.c
> > > @@ -116,13 +116,14 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
> > > ret = enc? crypto_skcipher_encrypt(req) : crypto_skcipher_decrypt(req);
> > > skcipher_request_zero(req);
> > > } else {
> > > + blkcipher_walk_init(&walk, dst, src, nbytes);
> > > +
> > > + ret = blkcipher_walk_virt(desc, &walk);
> > > +
> > > preempt_disable();
> > > pagefault_disable();
> > > enable_kernel_vsx();
> > >
> > > - blkcipher_walk_init(&walk, dst, src, nbytes);
> > > -
> > > - ret = blkcipher_walk_virt(desc, &walk);
> > > iv = walk.iv;
> > > memset(tweak, 0, AES_BLOCK_SIZE);
> > > aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
> > > @@ -135,13 +136,17 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
> > > aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
> > > nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
> > >
> > > + disable_kernel_vsx();
> > > + pagefault_enable();
> > > + preempt_enable();
> > > +
> > > nbytes &= AES_BLOCK_SIZE - 1;
> > > ret = blkcipher_walk_done(desc, &walk, nbytes);
> > > - }
> > >
> > > - disable_kernel_vsx();
> > > - pagefault_enable();
> > > - preempt_enable();
> > > + preempt_disable();
> > > + pagefault_disable();
> > > + enable_kernel_vsx();
> > > + }
>
> That doesn't seem right. It would leave preemption disabled when
> leaving the function.
Oh, right! Sorry, I will send a fixed v2 soon...
> > > }
> > > return ret;
> > > }
> > > --
> > > 2.17.1
> > >
>
> --
> Regards,
> Marcelo
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH] crypto: vmx - Fix sleep-in-atomic bugs
@ 2018-08-22 6:05 ` Ondrej Mosnáček
0 siblings, 0 replies; 17+ messages in thread
From: Ondrej Mosnáček @ 2018-08-22 6:05 UTC (permalink / raw)
To: marcelo.cerri
Cc: omosnace, Herbert Xu, linux-crypto, Stephan Mueller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
leo.barbosa, stable, Paulo Flabiano Smorigo, linuxppc-dev
ut 21. 8. 2018 o 18:41 Marcelo Henrique Cerri
<marcelo.cerri@canonical.com> nap=C3=ADsal(a):
> On Tue, Aug 21, 2018 at 05:24:45PM +0200, Ondrej Mosn=C3=A1=C4=8Dek wrote=
:
> > CC: Paulo Flabiano Smorigo <pfsmorigo@linux.vnet.ibm.com>,
> > linuxppc-dev@lists.ozlabs.org
> >
> > (Sorry, sent this before reading new e-mails in the thread...)
> >
> > ut 21. 8. 2018 o 17:18 Ondrej Mosnacek <omosnace@redhat.com> nap=C3=ADs=
al(a):
> > >
> > > This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
> > > implementations. The problem is that the blkcipher_* functions should
> > > not be called in atomic context.
> > >
> > > The bugs can be reproduced via the AF_ALG interface by trying to
> > > encrypt/decrypt sufficiently large buffers (at least 64 KiB) using th=
e
> > > VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
> > > trigger BUG in crypto_yield():
> > >
> > > [ 891.863680] BUG: sleeping function called from invalid context at =
include/crypto/algapi.h:424
> > > [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name: =
kcapi-enc
> > > [ 891.864739] 1 lock held by kcapi-enc/12347:
> > > [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at: skci=
pher_recvmsg+0x50/0x530
> > > [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted 4.19.0-0=
.rc0.git3.1.fc30.ppc64le #1
> > > [ 891.865251] Call Trace:
> > > [ 891.865340] [c0000003387578c0] [c000000000d67ea4] dump_stack+0xe8/=
0x164 (unreliable)
> > > [ 891.865511] [c000000338757910] [c000000000172a58] ___might_sleep+0=
x2f8/0x310
> > > [ 891.865679] [c000000338757990] [c0000000006bff74] blkcipher_walk_d=
one+0x374/0x4a0
> > > [ 891.865825] [c0000003387579e0] [d000000007e73e70] p8_aes_cbc_encry=
pt+0x1c8/0x260 [vmx_crypto]
> > > [ 891.865993] [c000000338757ad0] [c0000000006c0ee0] skcipher_encrypt=
_blkcipher+0x60/0x80
> > > [ 891.866128] [c000000338757b10] [c0000000006ec504] skcipher_recvmsg=
+0x424/0x530
> > > [ 891.866283] [c000000338757bd0] [c000000000b00654] sock_recvmsg+0x7=
4/0xa0
> > > [ 891.866403] [c000000338757c10] [c000000000b00f64] ___sys_recvmsg+0=
xf4/0x2f0
> > > [ 891.866515] [c000000338757d90] [c000000000b02bb8] __sys_recvmsg+0x=
68/0xe0
> > > [ 891.866631] [c000000338757e30] [c00000000000bbe4] system_call+0x5c=
/0x70
> > >
> > > Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX modul=
e")
> > > Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
> > > Cc: stable@vger.kernel.org
> > > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> > > ---
> > > This patch should fix the issue, but I didn't test it. (I'll see if I
> > > can find some time tomorrow to try and recompile the kernel on a PPC
> > > machine... in the meantime please review :)
> > >
> > > drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
> > > drivers/crypto/vmx/aes_xts.c | 19 ++++++++++++-------
> > > 2 files changed, 26 insertions(+), 23 deletions(-)
> > >
> > > diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cb=
c.c
> > > index 5285ece4f33a..b71895871be3 100644
> > > --- a/drivers/crypto/vmx/aes_cbc.c
> > > +++ b/drivers/crypto/vmx/aes_cbc.c
> > > @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct blkcipher_=
desc *desc,
> > > ret =3D crypto_skcipher_encrypt(req);
> > > skcipher_request_zero(req);
> > > } else {
> > > - preempt_disable();
> > > - pagefault_disable();
> > > - enable_kernel_vsx();
> > > -
> > > blkcipher_walk_init(&walk, dst, src, nbytes);
> > > ret =3D blkcipher_walk_virt(desc, &walk);
> > > while ((nbytes =3D walk.nbytes)) {
> > > + preempt_disable();
> > > + pagefault_disable();
> > > + enable_kernel_vsx();
> > > aes_p8_cbc_encrypt(walk.src.virt.addr,
> > > walk.dst.virt.addr,
> > > nbytes & AES_BLOCK_MASK,
> > > &ctx->enc_key, walk.iv, 1)=
;
> > > + disable_kernel_vsx();
> > > + pagefault_enable();
> > > + preempt_enable();
> > > +
> > > nbytes &=3D AES_BLOCK_SIZE - 1;
> > > ret =3D blkcipher_walk_done(desc, &walk, nbyt=
es);
> > > }
> > > -
> > > - disable_kernel_vsx();
> > > - pagefault_enable();
> > > - preempt_enable();
> > > }
> > >
> > > return ret;
> > > @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct blkcipher_=
desc *desc,
> > > ret =3D crypto_skcipher_decrypt(req);
> > > skcipher_request_zero(req);
> > > } else {
> > > - preempt_disable();
> > > - pagefault_disable();
> > > - enable_kernel_vsx();
> > > -
> > > blkcipher_walk_init(&walk, dst, src, nbytes);
> > > ret =3D blkcipher_walk_virt(desc, &walk);
> > > while ((nbytes =3D walk.nbytes)) {
> > > + preempt_disable();
> > > + pagefault_disable();
> > > + enable_kernel_vsx();
> > > aes_p8_cbc_encrypt(walk.src.virt.addr,
> > > walk.dst.virt.addr,
> > > nbytes & AES_BLOCK_MASK,
> > > &ctx->dec_key, walk.iv, 0)=
;
> > > + disable_kernel_vsx();
> > > + pagefault_enable();
> > > + preempt_enable();
> > > +
> > > nbytes &=3D AES_BLOCK_SIZE - 1;
> > > ret =3D blkcipher_walk_done(desc, &walk, nbyt=
es);
> > > }
> > > -
> > > - disable_kernel_vsx();
> > > - pagefault_enable();
> > > - preempt_enable();
> > > }
> > >
> > > return ret;
> > > diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xt=
s.c
> > > index 8bd9aff0f55f..016ef52390c9 100644
> > > --- a/drivers/crypto/vmx/aes_xts.c
> > > +++ b/drivers/crypto/vmx/aes_xts.c
> > > @@ -116,13 +116,14 @@ static int p8_aes_xts_crypt(struct blkcipher_de=
sc *desc,
> > > ret =3D enc? crypto_skcipher_encrypt(req) : crypto_sk=
cipher_decrypt(req);
> > > skcipher_request_zero(req);
> > > } else {
> > > + blkcipher_walk_init(&walk, dst, src, nbytes);
> > > +
> > > + ret =3D blkcipher_walk_virt(desc, &walk);
> > > +
> > > preempt_disable();
> > > pagefault_disable();
> > > enable_kernel_vsx();
> > >
> > > - blkcipher_walk_init(&walk, dst, src, nbytes);
> > > -
> > > - ret =3D blkcipher_walk_virt(desc, &walk);
> > > iv =3D walk.iv;
> > > memset(tweak, 0, AES_BLOCK_SIZE);
> > > aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
> > > @@ -135,13 +136,17 @@ static int p8_aes_xts_crypt(struct blkcipher_de=
sc *desc,
> > > aes_p8_xts_decrypt(walk.src.virt.addr=
, walk.dst.virt.addr,
> > > nbytes & AES_BLOCK_MA=
SK, &ctx->dec_key, NULL, tweak);
> > >
> > > + disable_kernel_vsx();
> > > + pagefault_enable();
> > > + preempt_enable();
> > > +
> > > nbytes &=3D AES_BLOCK_SIZE - 1;
> > > ret =3D blkcipher_walk_done(desc, &walk, nbyt=
es);
> > > - }
> > >
> > > - disable_kernel_vsx();
> > > - pagefault_enable();
> > > - preempt_enable();
> > > + preempt_disable();
> > > + pagefault_disable();
> > > + enable_kernel_vsx();
> > > + }
>
> That doesn't seem right. It would leave preemption disabled when
> leaving the function.
Oh, right! Sorry, I will send a fixed v2 soon...
> > > }
> > > return ret;
> > > }
> > > --
> > > 2.17.1
> > >
>
> --
> Regards,
> Marcelo
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v2] crypto: vmx - Fix sleep-in-atomic bugs
[not found] ` <CAAUqJDt_y04ts7Aq0U0fhXYRus2ckkEohBTkga0pjqfoQaBOCA@mail.gmail.com>
2018-08-21 15:03 ` Christophe LEROY
2018-08-21 15:16 ` [PATCH] crypto: vmx - Fix sleep-in-atomic bugs Ondrej Mosnacek
@ 2018-08-22 6:26 ` Ondrej Mosnacek
2018-08-23 0:04 ` Marcelo Henrique Cerri
2018-08-25 13:28 ` Herbert Xu
2 siblings, 2 replies; 17+ messages in thread
From: Ondrej Mosnacek @ 2018-08-22 6:26 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-crypto, Stephan Mueller, Benjamin Herrenschmidt,
Paul Mackerras, Michael Ellerman, Marcelo Henrique Cerri,
Leonidas S . Barbosa, Paulo Flabiano Smorigo, linuxppc-dev,
Ondrej Mosnacek, stable
This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
implementations. The problem is that the blkcipher_* functions should
not be called in atomic context.
The bugs can be reproduced via the AF_ALG interface by trying to
encrypt/decrypt sufficiently large buffers (at least 64 KiB) using the
VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
trigger BUG in crypto_yield():
[ 891.863680] BUG: sleeping function called from invalid context at include/crypto/algapi.h:424
[ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name: kcapi-enc
[ 891.864739] 1 lock held by kcapi-enc/12347:
[ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at: skcipher_recvmsg+0x50/0x530
[ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted 4.19.0-0.rc0.git3.1.fc30.ppc64le #1
[ 891.865251] Call Trace:
[ 891.865340] [c0000003387578c0] [c000000000d67ea4] dump_stack+0xe8/0x164 (unreliable)
[ 891.865511] [c000000338757910] [c000000000172a58] ___might_sleep+0x2f8/0x310
[ 891.865679] [c000000338757990] [c0000000006bff74] blkcipher_walk_done+0x374/0x4a0
[ 891.865825] [c0000003387579e0] [d000000007e73e70] p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto]
[ 891.865993] [c000000338757ad0] [c0000000006c0ee0] skcipher_encrypt_blkcipher+0x60/0x80
[ 891.866128] [c000000338757b10] [c0000000006ec504] skcipher_recvmsg+0x424/0x530
[ 891.866283] [c000000338757bd0] [c000000000b00654] sock_recvmsg+0x74/0xa0
[ 891.866403] [c000000338757c10] [c000000000b00f64] ___sys_recvmsg+0xf4/0x2f0
[ 891.866515] [c000000338757d90] [c000000000b02bb8] __sys_recvmsg+0x68/0xe0
[ 891.866631] [c000000338757e30] [c00000000000bbe4] system_call+0x5c/0x70
Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX module")
Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
Cc: stable@vger.kernel.org
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
---
Still untested, please test and review if possible.
Changes in v2:
- fix leaving preemtption, etc. disabled when leaving the function
(I switched to the more obvious and less efficient variant for the
sake of clarity.)
drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
drivers/crypto/vmx/aes_xts.c | 21 ++++++++++++++-------
2 files changed, 28 insertions(+), 23 deletions(-)
diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
index 5285ece4f33a..b71895871be3 100644
--- a/drivers/crypto/vmx/aes_cbc.c
+++ b/drivers/crypto/vmx/aes_cbc.c
@@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
ret = crypto_skcipher_encrypt(req);
skcipher_request_zero(req);
} else {
- preempt_disable();
- pagefault_disable();
- enable_kernel_vsx();
-
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
+ preempt_disable();
+ pagefault_disable();
+ enable_kernel_vsx();
aes_p8_cbc_encrypt(walk.src.virt.addr,
walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK,
&ctx->enc_key, walk.iv, 1);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
+
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
-
- disable_kernel_vsx();
- pagefault_enable();
- preempt_enable();
}
return ret;
@@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
ret = crypto_skcipher_decrypt(req);
skcipher_request_zero(req);
} else {
- preempt_disable();
- pagefault_disable();
- enable_kernel_vsx();
-
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
+ preempt_disable();
+ pagefault_disable();
+ enable_kernel_vsx();
aes_p8_cbc_encrypt(walk.src.virt.addr,
walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK,
&ctx->dec_key, walk.iv, 0);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
+
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
-
- disable_kernel_vsx();
- pagefault_enable();
- preempt_enable();
}
return ret;
diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c
index 8bd9aff0f55f..e9954a7d4694 100644
--- a/drivers/crypto/vmx/aes_xts.c
+++ b/drivers/crypto/vmx/aes_xts.c
@@ -116,32 +116,39 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
ret = enc? crypto_skcipher_encrypt(req) : crypto_skcipher_decrypt(req);
skcipher_request_zero(req);
} else {
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+
+ ret = blkcipher_walk_virt(desc, &walk);
+
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
- blkcipher_walk_init(&walk, dst, src, nbytes);
-
- ret = blkcipher_walk_virt(desc, &walk);
iv = walk.iv;
memset(tweak, 0, AES_BLOCK_SIZE);
aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
+
while ((nbytes = walk.nbytes)) {
+ preempt_disable();
+ pagefault_disable();
+ enable_kernel_vsx();
if (enc)
aes_p8_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK, &ctx->enc_key, NULL, tweak);
else
aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
-
- disable_kernel_vsx();
- pagefault_enable();
- preempt_enable();
}
return ret;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 17+ messages in thread
* Re: [PATCH v2] crypto: vmx - Fix sleep-in-atomic bugs
2018-08-22 6:26 ` [PATCH v2] " Ondrej Mosnacek
@ 2018-08-23 0:04 ` Marcelo Henrique Cerri
2018-08-23 20:34 ` Paulo Flabiano Smorigo
2018-08-25 13:28 ` Herbert Xu
1 sibling, 1 reply; 17+ messages in thread
From: Marcelo Henrique Cerri @ 2018-08-23 0:04 UTC (permalink / raw)
To: Ondrej Mosnacek
Cc: Herbert Xu, linux-crypto, Stephan Mueller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Leonidas S . Barbosa, Paulo Flabiano Smorigo, linuxppc-dev,
stable
[-- Attachment #1: Type: text/plain, Size: 6255 bytes --]
That looks good to me. Maybe Paulo can help testing it.
--
Regards,
Marcelo
On Wed, Aug 22, 2018 at 08:26:31AM +0200, Ondrej Mosnacek wrote:
> This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
> implementations. The problem is that the blkcipher_* functions should
> not be called in atomic context.
>
> The bugs can be reproduced via the AF_ALG interface by trying to
> encrypt/decrypt sufficiently large buffers (at least 64 KiB) using the
> VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
> trigger BUG in crypto_yield():
>
> [ 891.863680] BUG: sleeping function called from invalid context at include/crypto/algapi.h:424
> [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name: kcapi-enc
> [ 891.864739] 1 lock held by kcapi-enc/12347:
> [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at: skcipher_recvmsg+0x50/0x530
> [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted 4.19.0-0.rc0.git3.1.fc30.ppc64le #1
> [ 891.865251] Call Trace:
> [ 891.865340] [c0000003387578c0] [c000000000d67ea4] dump_stack+0xe8/0x164 (unreliable)
> [ 891.865511] [c000000338757910] [c000000000172a58] ___might_sleep+0x2f8/0x310
> [ 891.865679] [c000000338757990] [c0000000006bff74] blkcipher_walk_done+0x374/0x4a0
> [ 891.865825] [c0000003387579e0] [d000000007e73e70] p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto]
> [ 891.865993] [c000000338757ad0] [c0000000006c0ee0] skcipher_encrypt_blkcipher+0x60/0x80
> [ 891.866128] [c000000338757b10] [c0000000006ec504] skcipher_recvmsg+0x424/0x530
> [ 891.866283] [c000000338757bd0] [c000000000b00654] sock_recvmsg+0x74/0xa0
> [ 891.866403] [c000000338757c10] [c000000000b00f64] ___sys_recvmsg+0xf4/0x2f0
> [ 891.866515] [c000000338757d90] [c000000000b02bb8] __sys_recvmsg+0x68/0xe0
> [ 891.866631] [c000000338757e30] [c00000000000bbe4] system_call+0x5c/0x70
>
> Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX module")
> Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
> Cc: stable@vger.kernel.org
> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> ---
> Still untested, please test and review if possible.
>
> Changes in v2:
> - fix leaving preemtption, etc. disabled when leaving the function
> (I switched to the more obvious and less efficient variant for the
> sake of clarity.)
>
> drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
> drivers/crypto/vmx/aes_xts.c | 21 ++++++++++++++-------
> 2 files changed, 28 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
> index 5285ece4f33a..b71895871be3 100644
> --- a/drivers/crypto/vmx/aes_cbc.c
> +++ b/drivers/crypto/vmx/aes_cbc.c
> @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
> ret = crypto_skcipher_encrypt(req);
> skcipher_request_zero(req);
> } else {
> - preempt_disable();
> - pagefault_disable();
> - enable_kernel_vsx();
> -
> blkcipher_walk_init(&walk, dst, src, nbytes);
> ret = blkcipher_walk_virt(desc, &walk);
> while ((nbytes = walk.nbytes)) {
> + preempt_disable();
> + pagefault_disable();
> + enable_kernel_vsx();
> aes_p8_cbc_encrypt(walk.src.virt.addr,
> walk.dst.virt.addr,
> nbytes & AES_BLOCK_MASK,
> &ctx->enc_key, walk.iv, 1);
> + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
> +
> nbytes &= AES_BLOCK_SIZE - 1;
> ret = blkcipher_walk_done(desc, &walk, nbytes);
> }
> -
> - disable_kernel_vsx();
> - pagefault_enable();
> - preempt_enable();
> }
>
> return ret;
> @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
> ret = crypto_skcipher_decrypt(req);
> skcipher_request_zero(req);
> } else {
> - preempt_disable();
> - pagefault_disable();
> - enable_kernel_vsx();
> -
> blkcipher_walk_init(&walk, dst, src, nbytes);
> ret = blkcipher_walk_virt(desc, &walk);
> while ((nbytes = walk.nbytes)) {
> + preempt_disable();
> + pagefault_disable();
> + enable_kernel_vsx();
> aes_p8_cbc_encrypt(walk.src.virt.addr,
> walk.dst.virt.addr,
> nbytes & AES_BLOCK_MASK,
> &ctx->dec_key, walk.iv, 0);
> + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
> +
> nbytes &= AES_BLOCK_SIZE - 1;
> ret = blkcipher_walk_done(desc, &walk, nbytes);
> }
> -
> - disable_kernel_vsx();
> - pagefault_enable();
> - preempt_enable();
> }
>
> return ret;
> diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c
> index 8bd9aff0f55f..e9954a7d4694 100644
> --- a/drivers/crypto/vmx/aes_xts.c
> +++ b/drivers/crypto/vmx/aes_xts.c
> @@ -116,32 +116,39 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
> ret = enc? crypto_skcipher_encrypt(req) : crypto_skcipher_decrypt(req);
> skcipher_request_zero(req);
> } else {
> + blkcipher_walk_init(&walk, dst, src, nbytes);
> +
> + ret = blkcipher_walk_virt(desc, &walk);
> +
> preempt_disable();
> pagefault_disable();
> enable_kernel_vsx();
>
> - blkcipher_walk_init(&walk, dst, src, nbytes);
> -
> - ret = blkcipher_walk_virt(desc, &walk);
> iv = walk.iv;
> memset(tweak, 0, AES_BLOCK_SIZE);
> aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
>
> + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
> +
> while ((nbytes = walk.nbytes)) {
> + preempt_disable();
> + pagefault_disable();
> + enable_kernel_vsx();
> if (enc)
> aes_p8_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
> nbytes & AES_BLOCK_MASK, &ctx->enc_key, NULL, tweak);
> else
> aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
> nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
> + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
>
> nbytes &= AES_BLOCK_SIZE - 1;
> ret = blkcipher_walk_done(desc, &walk, nbytes);
> }
> -
> - disable_kernel_vsx();
> - pagefault_enable();
> - preempt_enable();
> }
> return ret;
> }
> --
> 2.17.1
>
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH v2] crypto: vmx - Fix sleep-in-atomic bugs
2018-08-23 0:04 ` Marcelo Henrique Cerri
@ 2018-08-23 20:34 ` Paulo Flabiano Smorigo
2018-08-24 19:47 ` Paulo Flabiano Smorigo
0 siblings, 1 reply; 17+ messages in thread
From: Paulo Flabiano Smorigo @ 2018-08-23 20:34 UTC (permalink / raw)
To: Marcelo Henrique Cerri
Cc: Ondrej Mosnacek, Herbert Xu, linux-crypto, Stephan Mueller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Leonidas S . Barbosa, linuxppc-dev, stable
On 2018-08-22 21:04, Marcelo Henrique Cerri wrote:
> That looks good to me. Maybe Paulo can help testing it.
>
> --
> Regards,
> Marcelo
>
> On Wed, Aug 22, 2018 at 08:26:31AM +0200, Ondrej Mosnacek wrote:
>> This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
>> implementations. The problem is that the blkcipher_* functions should
>> not be called in atomic context.
>>
>> The bugs can be reproduced via the AF_ALG interface by trying to
>> encrypt/decrypt sufficiently large buffers (at least 64 KiB) using the
>> VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
>> trigger BUG in crypto_yield():
>>
>> [ 891.863680] BUG: sleeping function called from invalid context at
>> include/crypto/algapi.h:424
>> [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name:
>> kcapi-enc
>> [ 891.864739] 1 lock held by kcapi-enc/12347:
>> [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at:
>> skcipher_recvmsg+0x50/0x530
>> [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted
>> 4.19.0-0.rc0.git3.1.fc30.ppc64le #1
>> [ 891.865251] Call Trace:
>> [ 891.865340] [c0000003387578c0] [c000000000d67ea4]
>> dump_stack+0xe8/0x164 (unreliable)
>> [ 891.865511] [c000000338757910] [c000000000172a58]
>> ___might_sleep+0x2f8/0x310
>> [ 891.865679] [c000000338757990] [c0000000006bff74]
>> blkcipher_walk_done+0x374/0x4a0
>> [ 891.865825] [c0000003387579e0] [d000000007e73e70]
>> p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto]
>> [ 891.865993] [c000000338757ad0] [c0000000006c0ee0]
>> skcipher_encrypt_blkcipher+0x60/0x80
>> [ 891.866128] [c000000338757b10] [c0000000006ec504]
>> skcipher_recvmsg+0x424/0x530
>> [ 891.866283] [c000000338757bd0] [c000000000b00654]
>> sock_recvmsg+0x74/0xa0
>> [ 891.866403] [c000000338757c10] [c000000000b00f64]
>> ___sys_recvmsg+0xf4/0x2f0
>> [ 891.866515] [c000000338757d90] [c000000000b02bb8]
>> __sys_recvmsg+0x68/0xe0
>> [ 891.866631] [c000000338757e30] [c00000000000bbe4]
>> system_call+0x5c/0x70
>>
>> Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX
>> module")
>> Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
>> ---
>> Still untested, please test and review if possible.
>>
>> Changes in v2:
>> - fix leaving preemtption, etc. disabled when leaving the function
>> (I switched to the more obvious and less efficient variant for the
>> sake of clarity.)
>>
>> drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
>> drivers/crypto/vmx/aes_xts.c | 21 ++++++++++++++-------
>> 2 files changed, 28 insertions(+), 23 deletions(-)
>>
>> diff --git a/drivers/crypto/vmx/aes_cbc.c
>> b/drivers/crypto/vmx/aes_cbc.c
>> index 5285ece4f33a..b71895871be3 100644
>> --- a/drivers/crypto/vmx/aes_cbc.c
>> +++ b/drivers/crypto/vmx/aes_cbc.c
>> @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct
>> blkcipher_desc *desc,
>> ret = crypto_skcipher_encrypt(req);
>> skcipher_request_zero(req);
>> } else {
>> - preempt_disable();
>> - pagefault_disable();
>> - enable_kernel_vsx();
>> -
>> blkcipher_walk_init(&walk, dst, src, nbytes);
>> ret = blkcipher_walk_virt(desc, &walk);
>> while ((nbytes = walk.nbytes)) {
>> + preempt_disable();
>> + pagefault_disable();
>> + enable_kernel_vsx();
>> aes_p8_cbc_encrypt(walk.src.virt.addr,
>> walk.dst.virt.addr,
>> nbytes & AES_BLOCK_MASK,
>> &ctx->enc_key, walk.iv, 1);
>> + disable_kernel_vsx();
>> + pagefault_enable();
>> + preempt_enable();
>> +
>> nbytes &= AES_BLOCK_SIZE - 1;
>> ret = blkcipher_walk_done(desc, &walk, nbytes);
>> }
>> -
>> - disable_kernel_vsx();
>> - pagefault_enable();
>> - preempt_enable();
>> }
>>
>> return ret;
>> @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct
>> blkcipher_desc *desc,
>> ret = crypto_skcipher_decrypt(req);
>> skcipher_request_zero(req);
>> } else {
>> - preempt_disable();
>> - pagefault_disable();
>> - enable_kernel_vsx();
>> -
>> blkcipher_walk_init(&walk, dst, src, nbytes);
>> ret = blkcipher_walk_virt(desc, &walk);
>> while ((nbytes = walk.nbytes)) {
>> + preempt_disable();
>> + pagefault_disable();
>> + enable_kernel_vsx();
>> aes_p8_cbc_encrypt(walk.src.virt.addr,
>> walk.dst.virt.addr,
>> nbytes & AES_BLOCK_MASK,
>> &ctx->dec_key, walk.iv, 0);
>> + disable_kernel_vsx();
>> + pagefault_enable();
>> + preempt_enable();
>> +
>> nbytes &= AES_BLOCK_SIZE - 1;
>> ret = blkcipher_walk_done(desc, &walk, nbytes);
>> }
>> -
>> - disable_kernel_vsx();
>> - pagefault_enable();
>> - preempt_enable();
>> }
>>
>> return ret;
>> diff --git a/drivers/crypto/vmx/aes_xts.c
>> b/drivers/crypto/vmx/aes_xts.c
>> index 8bd9aff0f55f..e9954a7d4694 100644
>> --- a/drivers/crypto/vmx/aes_xts.c
>> +++ b/drivers/crypto/vmx/aes_xts.c
>> @@ -116,32 +116,39 @@ static int p8_aes_xts_crypt(struct
>> blkcipher_desc *desc,
>> ret = enc? crypto_skcipher_encrypt(req) :
>> crypto_skcipher_decrypt(req);
>> skcipher_request_zero(req);
>> } else {
>> + blkcipher_walk_init(&walk, dst, src, nbytes);
>> +
>> + ret = blkcipher_walk_virt(desc, &walk);
>> +
>> preempt_disable();
>> pagefault_disable();
>> enable_kernel_vsx();
>>
>> - blkcipher_walk_init(&walk, dst, src, nbytes);
>> -
>> - ret = blkcipher_walk_virt(desc, &walk);
>> iv = walk.iv;
>> memset(tweak, 0, AES_BLOCK_SIZE);
>> aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
>>
>> + disable_kernel_vsx();
>> + pagefault_enable();
>> + preempt_enable();
>> +
>> while ((nbytes = walk.nbytes)) {
>> + preempt_disable();
>> + pagefault_disable();
>> + enable_kernel_vsx();
>> if (enc)
>> aes_p8_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
>> nbytes & AES_BLOCK_MASK, &ctx->enc_key, NULL, tweak);
>> else
>> aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
>> nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
>> + disable_kernel_vsx();
>> + pagefault_enable();
>> + preempt_enable();
>>
>> nbytes &= AES_BLOCK_SIZE - 1;
>> ret = blkcipher_walk_done(desc, &walk, nbytes);
>> }
>> -
>> - disable_kernel_vsx();
>> - pagefault_enable();
>> - preempt_enable();
>> }
>> return ret;
>> }
>> --
>> 2.17.1
>>
Sure thing. I'll test it later today. Thanks Ondrej for the fix.
--
Paulo Flabiano Smorigo
IBM Linux Technology Center
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH v2] crypto: vmx - Fix sleep-in-atomic bugs
2018-08-23 20:34 ` Paulo Flabiano Smorigo
@ 2018-08-24 19:47 ` Paulo Flabiano Smorigo
2018-08-24 20:01 ` Ondrej Mosnacek
0 siblings, 1 reply; 17+ messages in thread
From: Paulo Flabiano Smorigo @ 2018-08-24 19:47 UTC (permalink / raw)
To: Marcelo Henrique Cerri
Cc: Ondrej Mosnacek, Herbert Xu, linux-crypto, Stephan Mueller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Leonidas S . Barbosa, linuxppc-dev, stable
On 2018-08-23 17:34, Paulo Flabiano Smorigo wrote:
> On 2018-08-22 21:04, Marcelo Henrique Cerri wrote:
>> That looks good to me. Maybe Paulo can help testing it.
>>
>> --
>> Regards,
>> Marcelo
>>
>> On Wed, Aug 22, 2018 at 08:26:31AM +0200, Ondrej Mosnacek wrote:
>>> This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
>>> implementations. The problem is that the blkcipher_* functions should
>>> not be called in atomic context.
>>>
>>> The bugs can be reproduced via the AF_ALG interface by trying to
>>> encrypt/decrypt sufficiently large buffers (at least 64 KiB) using
>>> the
>>> VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
>>> trigger BUG in crypto_yield():
>>>
>>> [ 891.863680] BUG: sleeping function called from invalid context at
>>> include/crypto/algapi.h:424
>>> [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name:
>>> kcapi-enc
>>> [ 891.864739] 1 lock held by kcapi-enc/12347:
>>> [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at:
>>> skcipher_recvmsg+0x50/0x530
>>> [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted
>>> 4.19.0-0.rc0.git3.1.fc30.ppc64le #1
>>> [ 891.865251] Call Trace:
>>> [ 891.865340] [c0000003387578c0] [c000000000d67ea4]
>>> dump_stack+0xe8/0x164 (unreliable)
>>> [ 891.865511] [c000000338757910] [c000000000172a58]
>>> ___might_sleep+0x2f8/0x310
>>> [ 891.865679] [c000000338757990] [c0000000006bff74]
>>> blkcipher_walk_done+0x374/0x4a0
>>> [ 891.865825] [c0000003387579e0] [d000000007e73e70]
>>> p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto]
>>> [ 891.865993] [c000000338757ad0] [c0000000006c0ee0]
>>> skcipher_encrypt_blkcipher+0x60/0x80
>>> [ 891.866128] [c000000338757b10] [c0000000006ec504]
>>> skcipher_recvmsg+0x424/0x530
>>> [ 891.866283] [c000000338757bd0] [c000000000b00654]
>>> sock_recvmsg+0x74/0xa0
>>> [ 891.866403] [c000000338757c10] [c000000000b00f64]
>>> ___sys_recvmsg+0xf4/0x2f0
>>> [ 891.866515] [c000000338757d90] [c000000000b02bb8]
>>> __sys_recvmsg+0x68/0xe0
>>> [ 891.866631] [c000000338757e30] [c00000000000bbe4]
>>> system_call+0x5c/0x70
>>>
>>> Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX
>>> module")
>>> Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
>>> Cc: stable@vger.kernel.org
>>> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
>>> ---
>>> Still untested, please test and review if possible.
>>>
>>> Changes in v2:
>>> - fix leaving preemtption, etc. disabled when leaving the function
>>> (I switched to the more obvious and less efficient variant for the
>>> sake of clarity.)
>>>
>>> drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
>>> drivers/crypto/vmx/aes_xts.c | 21 ++++++++++++++-------
>>> 2 files changed, 28 insertions(+), 23 deletions(-)
>>>
>>> diff --git a/drivers/crypto/vmx/aes_cbc.c
>>> b/drivers/crypto/vmx/aes_cbc.c
>>> index 5285ece4f33a..b71895871be3 100644
>>> --- a/drivers/crypto/vmx/aes_cbc.c
>>> +++ b/drivers/crypto/vmx/aes_cbc.c
>>> @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct
>>> blkcipher_desc *desc,
>>> ret = crypto_skcipher_encrypt(req);
>>> skcipher_request_zero(req);
>>> } else {
>>> - preempt_disable();
>>> - pagefault_disable();
>>> - enable_kernel_vsx();
>>> -
>>> blkcipher_walk_init(&walk, dst, src, nbytes);
>>> ret = blkcipher_walk_virt(desc, &walk);
>>> while ((nbytes = walk.nbytes)) {
>>> + preempt_disable();
>>> + pagefault_disable();
>>> + enable_kernel_vsx();
>>> aes_p8_cbc_encrypt(walk.src.virt.addr,
>>> walk.dst.virt.addr,
>>> nbytes & AES_BLOCK_MASK,
>>> &ctx->enc_key, walk.iv, 1);
>>> + disable_kernel_vsx();
>>> + pagefault_enable();
>>> + preempt_enable();
>>> +
>>> nbytes &= AES_BLOCK_SIZE - 1;
>>> ret = blkcipher_walk_done(desc, &walk, nbytes);
>>> }
>>> -
>>> - disable_kernel_vsx();
>>> - pagefault_enable();
>>> - preempt_enable();
>>> }
>>>
>>> return ret;
>>> @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct
>>> blkcipher_desc *desc,
>>> ret = crypto_skcipher_decrypt(req);
>>> skcipher_request_zero(req);
>>> } else {
>>> - preempt_disable();
>>> - pagefault_disable();
>>> - enable_kernel_vsx();
>>> -
>>> blkcipher_walk_init(&walk, dst, src, nbytes);
>>> ret = blkcipher_walk_virt(desc, &walk);
>>> while ((nbytes = walk.nbytes)) {
>>> + preempt_disable();
>>> + pagefault_disable();
>>> + enable_kernel_vsx();
>>> aes_p8_cbc_encrypt(walk.src.virt.addr,
>>> walk.dst.virt.addr,
>>> nbytes & AES_BLOCK_MASK,
>>> &ctx->dec_key, walk.iv, 0);
>>> + disable_kernel_vsx();
>>> + pagefault_enable();
>>> + preempt_enable();
>>> +
>>> nbytes &= AES_BLOCK_SIZE - 1;
>>> ret = blkcipher_walk_done(desc, &walk, nbytes);
>>> }
>>> -
>>> - disable_kernel_vsx();
>>> - pagefault_enable();
>>> - preempt_enable();
>>> }
>>>
>>> return ret;
>>> diff --git a/drivers/crypto/vmx/aes_xts.c
>>> b/drivers/crypto/vmx/aes_xts.c
>>> index 8bd9aff0f55f..e9954a7d4694 100644
>>> --- a/drivers/crypto/vmx/aes_xts.c
>>> +++ b/drivers/crypto/vmx/aes_xts.c
>>> @@ -116,32 +116,39 @@ static int p8_aes_xts_crypt(struct
>>> blkcipher_desc *desc,
>>> ret = enc? crypto_skcipher_encrypt(req) :
>>> crypto_skcipher_decrypt(req);
>>> skcipher_request_zero(req);
>>> } else {
>>> + blkcipher_walk_init(&walk, dst, src, nbytes);
>>> +
>>> + ret = blkcipher_walk_virt(desc, &walk);
>>> +
>>> preempt_disable();
>>> pagefault_disable();
>>> enable_kernel_vsx();
>>>
>>> - blkcipher_walk_init(&walk, dst, src, nbytes);
>>> -
>>> - ret = blkcipher_walk_virt(desc, &walk);
>>> iv = walk.iv;
>>> memset(tweak, 0, AES_BLOCK_SIZE);
>>> aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
>>>
>>> + disable_kernel_vsx();
>>> + pagefault_enable();
>>> + preempt_enable();
>>> +
>>> while ((nbytes = walk.nbytes)) {
>>> + preempt_disable();
>>> + pagefault_disable();
>>> + enable_kernel_vsx();
>>> if (enc)
>>> aes_p8_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
>>> nbytes & AES_BLOCK_MASK, &ctx->enc_key, NULL, tweak);
>>> else
>>> aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
>>> nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
>>> + disable_kernel_vsx();
>>> + pagefault_enable();
>>> + preempt_enable();
>>>
>>> nbytes &= AES_BLOCK_SIZE - 1;
>>> ret = blkcipher_walk_done(desc, &walk, nbytes);
>>> }
>>> -
>>> - disable_kernel_vsx();
>>> - pagefault_enable();
>>> - preempt_enable();
>>> }
>>> return ret;
>>> }
>>> --
>>> 2.17.1
>>>
>
> Sure thing. I'll test it later today. Thanks Ondrej for the fix.
Looks good to me. I made some tests here and no problem was found.
--
Paulo Flabiano Smorigo
IBM Linux Technology Center
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH v2] crypto: vmx - Fix sleep-in-atomic bugs
2018-08-24 19:47 ` Paulo Flabiano Smorigo
@ 2018-08-24 20:01 ` Ondrej Mosnacek
0 siblings, 0 replies; 17+ messages in thread
From: Ondrej Mosnacek @ 2018-08-24 20:01 UTC (permalink / raw)
To: Paulo Flabiano Smorigo
Cc: Marcelo Henrique Cerri, Herbert Xu, linux-crypto,
Stephan Mueller, Benjamin Herrenschmidt, Paul Mackerras,
Michael Ellerman, Leonidas S . Barbosa, linuxppc-dev, stable
On Fri, Aug 24, 2018 at 9:39 PM Paulo Flabiano Smorigo
<pfsmorigo@linux.vnet.ibm.com> wrote:
> On 2018-08-23 17:34, Paulo Flabiano Smorigo wrote:
> > On 2018-08-22 21:04, Marcelo Henrique Cerri wrote:
> >> That looks good to me. Maybe Paulo can help testing it.
> >>
> >> --
> >> Regards,
> >> Marcelo
> >>
> >> On Wed, Aug 22, 2018 at 08:26:31AM +0200, Ondrej Mosnacek wrote:
> >>> This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
> >>> implementations. The problem is that the blkcipher_* functions should
> >>> not be called in atomic context.
> >>>
> >>> The bugs can be reproduced via the AF_ALG interface by trying to
> >>> encrypt/decrypt sufficiently large buffers (at least 64 KiB) using
> >>> the
> >>> VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
> >>> trigger BUG in crypto_yield():
> >>>
> >>> [ 891.863680] BUG: sleeping function called from invalid context at
> >>> include/crypto/algapi.h:424
> >>> [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name:
> >>> kcapi-enc
> >>> [ 891.864739] 1 lock held by kcapi-enc/12347:
> >>> [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at:
> >>> skcipher_recvmsg+0x50/0x530
> >>> [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted
> >>> 4.19.0-0.rc0.git3.1.fc30.ppc64le #1
> >>> [ 891.865251] Call Trace:
> >>> [ 891.865340] [c0000003387578c0] [c000000000d67ea4]
> >>> dump_stack+0xe8/0x164 (unreliable)
> >>> [ 891.865511] [c000000338757910] [c000000000172a58]
> >>> ___might_sleep+0x2f8/0x310
> >>> [ 891.865679] [c000000338757990] [c0000000006bff74]
> >>> blkcipher_walk_done+0x374/0x4a0
> >>> [ 891.865825] [c0000003387579e0] [d000000007e73e70]
> >>> p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto]
> >>> [ 891.865993] [c000000338757ad0] [c0000000006c0ee0]
> >>> skcipher_encrypt_blkcipher+0x60/0x80
> >>> [ 891.866128] [c000000338757b10] [c0000000006ec504]
> >>> skcipher_recvmsg+0x424/0x530
> >>> [ 891.866283] [c000000338757bd0] [c000000000b00654]
> >>> sock_recvmsg+0x74/0xa0
> >>> [ 891.866403] [c000000338757c10] [c000000000b00f64]
> >>> ___sys_recvmsg+0xf4/0x2f0
> >>> [ 891.866515] [c000000338757d90] [c000000000b02bb8]
> >>> __sys_recvmsg+0x68/0xe0
> >>> [ 891.866631] [c000000338757e30] [c00000000000bbe4]
> >>> system_call+0x5c/0x70
> >>>
> >>> Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX
> >>> module")
> >>> Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
> >>> Cc: stable@vger.kernel.org
> >>> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> >>> ---
> >>> Still untested, please test and review if possible.
> >>>
> >>> Changes in v2:
> >>> - fix leaving preemtption, etc. disabled when leaving the function
> >>> (I switched to the more obvious and less efficient variant for the
> >>> sake of clarity.)
> >>>
> >>> drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
> >>> drivers/crypto/vmx/aes_xts.c | 21 ++++++++++++++-------
> >>> 2 files changed, 28 insertions(+), 23 deletions(-)
> >>>
> >>> diff --git a/drivers/crypto/vmx/aes_cbc.c
> >>> b/drivers/crypto/vmx/aes_cbc.c
> >>> index 5285ece4f33a..b71895871be3 100644
> >>> --- a/drivers/crypto/vmx/aes_cbc.c
> >>> +++ b/drivers/crypto/vmx/aes_cbc.c
> >>> @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct
> >>> blkcipher_desc *desc,
> >>> ret = crypto_skcipher_encrypt(req);
> >>> skcipher_request_zero(req);
> >>> } else {
> >>> - preempt_disable();
> >>> - pagefault_disable();
> >>> - enable_kernel_vsx();
> >>> -
> >>> blkcipher_walk_init(&walk, dst, src, nbytes);
> >>> ret = blkcipher_walk_virt(desc, &walk);
> >>> while ((nbytes = walk.nbytes)) {
> >>> + preempt_disable();
> >>> + pagefault_disable();
> >>> + enable_kernel_vsx();
> >>> aes_p8_cbc_encrypt(walk.src.virt.addr,
> >>> walk.dst.virt.addr,
> >>> nbytes & AES_BLOCK_MASK,
> >>> &ctx->enc_key, walk.iv, 1);
> >>> + disable_kernel_vsx();
> >>> + pagefault_enable();
> >>> + preempt_enable();
> >>> +
> >>> nbytes &= AES_BLOCK_SIZE - 1;
> >>> ret = blkcipher_walk_done(desc, &walk, nbytes);
> >>> }
> >>> -
> >>> - disable_kernel_vsx();
> >>> - pagefault_enable();
> >>> - preempt_enable();
> >>> }
> >>>
> >>> return ret;
> >>> @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct
> >>> blkcipher_desc *desc,
> >>> ret = crypto_skcipher_decrypt(req);
> >>> skcipher_request_zero(req);
> >>> } else {
> >>> - preempt_disable();
> >>> - pagefault_disable();
> >>> - enable_kernel_vsx();
> >>> -
> >>> blkcipher_walk_init(&walk, dst, src, nbytes);
> >>> ret = blkcipher_walk_virt(desc, &walk);
> >>> while ((nbytes = walk.nbytes)) {
> >>> + preempt_disable();
> >>> + pagefault_disable();
> >>> + enable_kernel_vsx();
> >>> aes_p8_cbc_encrypt(walk.src.virt.addr,
> >>> walk.dst.virt.addr,
> >>> nbytes & AES_BLOCK_MASK,
> >>> &ctx->dec_key, walk.iv, 0);
> >>> + disable_kernel_vsx();
> >>> + pagefault_enable();
> >>> + preempt_enable();
> >>> +
> >>> nbytes &= AES_BLOCK_SIZE - 1;
> >>> ret = blkcipher_walk_done(desc, &walk, nbytes);
> >>> }
> >>> -
> >>> - disable_kernel_vsx();
> >>> - pagefault_enable();
> >>> - preempt_enable();
> >>> }
> >>>
> >>> return ret;
> >>> diff --git a/drivers/crypto/vmx/aes_xts.c
> >>> b/drivers/crypto/vmx/aes_xts.c
> >>> index 8bd9aff0f55f..e9954a7d4694 100644
> >>> --- a/drivers/crypto/vmx/aes_xts.c
> >>> +++ b/drivers/crypto/vmx/aes_xts.c
> >>> @@ -116,32 +116,39 @@ static int p8_aes_xts_crypt(struct
> >>> blkcipher_desc *desc,
> >>> ret = enc? crypto_skcipher_encrypt(req) :
> >>> crypto_skcipher_decrypt(req);
> >>> skcipher_request_zero(req);
> >>> } else {
> >>> + blkcipher_walk_init(&walk, dst, src, nbytes);
> >>> +
> >>> + ret = blkcipher_walk_virt(desc, &walk);
> >>> +
> >>> preempt_disable();
> >>> pagefault_disable();
> >>> enable_kernel_vsx();
> >>>
> >>> - blkcipher_walk_init(&walk, dst, src, nbytes);
> >>> -
> >>> - ret = blkcipher_walk_virt(desc, &walk);
> >>> iv = walk.iv;
> >>> memset(tweak, 0, AES_BLOCK_SIZE);
> >>> aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
> >>>
> >>> + disable_kernel_vsx();
> >>> + pagefault_enable();
> >>> + preempt_enable();
> >>> +
> >>> while ((nbytes = walk.nbytes)) {
> >>> + preempt_disable();
> >>> + pagefault_disable();
> >>> + enable_kernel_vsx();
> >>> if (enc)
> >>> aes_p8_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
> >>> nbytes & AES_BLOCK_MASK, &ctx->enc_key, NULL, tweak);
> >>> else
> >>> aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
> >>> nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
> >>> + disable_kernel_vsx();
> >>> + pagefault_enable();
> >>> + preempt_enable();
> >>>
> >>> nbytes &= AES_BLOCK_SIZE - 1;
> >>> ret = blkcipher_walk_done(desc, &walk, nbytes);
> >>> }
> >>> -
> >>> - disable_kernel_vsx();
> >>> - pagefault_enable();
> >>> - preempt_enable();
> >>> }
> >>> return ret;
> >>> }
> >>> --
> >>> 2.17.1
> >>>
> >
> > Sure thing. I'll test it later today. Thanks Ondrej for the fix.
>
> Looks good to me. I made some tests here and no problem was found.
Great, thanks!
--
Ondrej Mosnacek <omosnace at redhat dot com>
Associate Software Engineer, Security Technologies
Red Hat, Inc.
^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [PATCH v2] crypto: vmx - Fix sleep-in-atomic bugs
2018-08-22 6:26 ` [PATCH v2] " Ondrej Mosnacek
2018-08-23 0:04 ` Marcelo Henrique Cerri
@ 2018-08-25 13:28 ` Herbert Xu
1 sibling, 0 replies; 17+ messages in thread
From: Herbert Xu @ 2018-08-25 13:28 UTC (permalink / raw)
To: Ondrej Mosnacek
Cc: linux-crypto, Stephan Mueller, Benjamin Herrenschmidt,
Paul Mackerras, Michael Ellerman, Marcelo Henrique Cerri,
Leonidas S . Barbosa, Paulo Flabiano Smorigo, linuxppc-dev,
stable
On Wed, Aug 22, 2018 at 08:26:31AM +0200, Ondrej Mosnacek wrote:
> This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX
> implementations. The problem is that the blkcipher_* functions should
> not be called in atomic context.
>
> The bugs can be reproduced via the AF_ALG interface by trying to
> encrypt/decrypt sufficiently large buffers (at least 64 KiB) using the
> VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then
> trigger BUG in crypto_yield():
>
> [ 891.863680] BUG: sleeping function called from invalid context at include/crypto/algapi.h:424
> [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name: kcapi-enc
> [ 891.864739] 1 lock held by kcapi-enc/12347:
> [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at: skcipher_recvmsg+0x50/0x530
> [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted 4.19.0-0.rc0.git3.1.fc30.ppc64le #1
> [ 891.865251] Call Trace:
> [ 891.865340] [c0000003387578c0] [c000000000d67ea4] dump_stack+0xe8/0x164 (unreliable)
> [ 891.865511] [c000000338757910] [c000000000172a58] ___might_sleep+0x2f8/0x310
> [ 891.865679] [c000000338757990] [c0000000006bff74] blkcipher_walk_done+0x374/0x4a0
> [ 891.865825] [c0000003387579e0] [d000000007e73e70] p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto]
> [ 891.865993] [c000000338757ad0] [c0000000006c0ee0] skcipher_encrypt_blkcipher+0x60/0x80
> [ 891.866128] [c000000338757b10] [c0000000006ec504] skcipher_recvmsg+0x424/0x530
> [ 891.866283] [c000000338757bd0] [c000000000b00654] sock_recvmsg+0x74/0xa0
> [ 891.866403] [c000000338757c10] [c000000000b00f64] ___sys_recvmsg+0xf4/0x2f0
> [ 891.866515] [c000000338757d90] [c000000000b02bb8] __sys_recvmsg+0x68/0xe0
> [ 891.866631] [c000000338757e30] [c00000000000bbe4] system_call+0x5c/0x70
>
> Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX module")
> Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS")
> Cc: stable@vger.kernel.org
> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Patch applied. Thanks.
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
^ permalink raw reply [flat|nested] 17+ messages in thread
end of thread, other threads:[~2018-08-25 13:28 UTC | newest]
Thread overview: 17+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[not found] <CAAUqJDvErj0Y4=GBtXgvBRON7MEic7_-jBZNvjacwcOd0TF_2g@mail.gmail.com>
[not found] ` <3627129.cWTIy1uDMC@tauon.chronox.de>
[not found] ` <CAAUqJDt_y04ts7Aq0U0fhXYRus2ckkEohBTkga0pjqfoQaBOCA@mail.gmail.com>
2018-08-21 15:03 ` BUG: libkcapi tests trigger sleep-in-atomic bug in VMX code (ppc64) Christophe LEROY
2018-08-21 15:03 ` Christophe LEROY
2018-08-21 15:12 ` Marcelo Henrique Cerri
2018-08-21 15:12 ` Marcelo Henrique Cerri
2018-08-21 15:16 ` [PATCH] crypto: vmx - Fix sleep-in-atomic bugs Ondrej Mosnacek
2018-08-21 15:24 ` Ondrej Mosnáček
2018-08-21 15:24 ` Ondrej Mosnáček
2018-08-21 16:41 ` Marcelo Henrique Cerri
2018-08-21 16:41 ` Marcelo Henrique Cerri
2018-08-22 6:05 ` Ondrej Mosnáček
2018-08-22 6:05 ` Ondrej Mosnáček
2018-08-22 6:26 ` [PATCH v2] " Ondrej Mosnacek
2018-08-23 0:04 ` Marcelo Henrique Cerri
2018-08-23 20:34 ` Paulo Flabiano Smorigo
2018-08-24 19:47 ` Paulo Flabiano Smorigo
2018-08-24 20:01 ` Ondrej Mosnacek
2018-08-25 13:28 ` Herbert Xu
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