* [PATCH v2] KEYS: trusted: Fix memory leak in tpm2_key_encode()
@ 2022-06-08 13:17 Jianglei Nie
2022-06-08 13:38 ` Jonathan McDowell
2022-06-09 5:21 ` [PATCH v2] " Jarkko Sakkinen
0 siblings, 2 replies; 8+ messages in thread
From: Jianglei Nie @ 2022-06-08 13:17 UTC (permalink / raw)
To: jejb, jarkko, zohar, dhowells, jmorris, serge
Cc: linux-integrity, keyrings, linux-security-module, linux-kernel,
Jianglei Nie
tpm2_key_encode() allocates a memory chunk from scratch with kmalloc(),
but it is never freed, which leads to a memory leak. Free the memory
chunk with kfree() in the return path.
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
---
security/keys/trusted-keys/trusted_tpm2.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 0165da386289..8b7ab22950d1 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -32,6 +32,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
struct trusted_key_options *options,
u8 *src, u32 len)
{
+ int err;
const int SCRATCH_SIZE = PAGE_SIZE;
u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
u8 *work = scratch, *work1;
@@ -57,8 +58,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
unsigned char bool[3], *w = bool;
/* tag 0 is emptyAuth */
w = asn1_encode_boolean(w, w + sizeof(bool), true);
- if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
- return PTR_ERR(w);
+ if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) {
+ err = PTR_ERR(w);
+ goto out;
+ }
work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
}
@@ -69,8 +72,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
* trigger, so if it does there's something nefarious going on
*/
if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
- "BUG: scratch buffer is too small"))
- return -EINVAL;
+ "BUG: scratch buffer is too small")) {
+ err = -EINVAL;
+ goto out;
+ }
work = asn1_encode_integer(work, end_work, options->keyhandle);
work = asn1_encode_octet_string(work, end_work, pub, pub_len);
@@ -79,10 +84,16 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
work1 = payload->blob;
work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
scratch, work - scratch);
- if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
- return PTR_ERR(work1);
+ if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) {
+ err = -EINVAL;
+ goto out;
+ }
+ kfree(scratch);
return work1 - payload->blob;
+
+out:
+ return err;
}
struct tpm2_key_context {
--
2.25.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v2] KEYS: trusted: Fix memory leak in tpm2_key_encode()
2022-06-08 13:17 [PATCH v2] KEYS: trusted: Fix memory leak in tpm2_key_encode() Jianglei Nie
@ 2022-06-08 13:38 ` Jonathan McDowell
2022-06-09 5:28 ` jarkko
2022-06-09 5:21 ` [PATCH v2] " Jarkko Sakkinen
1 sibling, 1 reply; 8+ messages in thread
From: Jonathan McDowell @ 2022-06-08 13:38 UTC (permalink / raw)
To: Jianglei Nie
Cc: jejb, jarkko, zohar, dhowells, jmorris, serge, linux-integrity,
keyrings, linux-security-module, linux-kernel
On Wed, Jun 08, 2022 at 09:17:32PM +0800, Jianglei Nie wrote:
> tpm2_key_encode() allocates a memory chunk from scratch with kmalloc(),
> but it is never freed, which leads to a memory leak. Free the memory
> chunk with kfree() in the return path.
This change only does the kfree in the success path; "out" just returns
the error without freeing the memory.
> Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
> ---
> security/keys/trusted-keys/trusted_tpm2.c | 23 +++++++++++++++++------
> 1 file changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
> index 0165da386289..8b7ab22950d1 100644
> --- a/security/keys/trusted-keys/trusted_tpm2.c
> +++ b/security/keys/trusted-keys/trusted_tpm2.c
> @@ -32,6 +32,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> struct trusted_key_options *options,
> u8 *src, u32 len)
> {
> + int err;
> const int SCRATCH_SIZE = PAGE_SIZE;
> u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
> u8 *work = scratch, *work1;
> @@ -57,8 +58,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> unsigned char bool[3], *w = bool;
> /* tag 0 is emptyAuth */
> w = asn1_encode_boolean(w, w + sizeof(bool), true);
> - if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
> - return PTR_ERR(w);
> + if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) {
> + err = PTR_ERR(w);
> + goto out;
> + }
> work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
> }
>
> @@ -69,8 +72,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> * trigger, so if it does there's something nefarious going on
> */
> if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
> - "BUG: scratch buffer is too small"))
> - return -EINVAL;
> + "BUG: scratch buffer is too small")) {
> + err = -EINVAL;
> + goto out;
> + }
>
> work = asn1_encode_integer(work, end_work, options->keyhandle);
> work = asn1_encode_octet_string(work, end_work, pub, pub_len);
> @@ -79,10 +84,16 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> work1 = payload->blob;
> work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
> scratch, work - scratch);
> - if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
> - return PTR_ERR(work1);
> + if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) {
> + err = -EINVAL;
> + goto out;
> + }
> + kfree(scratch);
>
> return work1 - payload->blob;
> +
> +out:
> + return err;
> }
>
> struct tpm2_key_context {
> --
> 2.25.1
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] KEYS: trusted: Fix memory leak in tpm2_key_encode()
2022-06-08 13:17 [PATCH v2] KEYS: trusted: Fix memory leak in tpm2_key_encode() Jianglei Nie
2022-06-08 13:38 ` Jonathan McDowell
@ 2022-06-09 5:21 ` Jarkko Sakkinen
2022-06-09 5:22 ` Jarkko Sakkinen
1 sibling, 1 reply; 8+ messages in thread
From: Jarkko Sakkinen @ 2022-06-09 5:21 UTC (permalink / raw)
To: Jianglei Nie
Cc: jejb, zohar, dhowells, jmorris, serge, linux-integrity, keyrings,
linux-security-module, linux-kernel
On Wed, Jun 08, 2022 at 09:17:32PM +0800, Jianglei Nie wrote:
> tpm2_key_encode() allocates a memory chunk from scratch with kmalloc(),
> but it is never freed, which leads to a memory leak. Free the memory
> chunk with kfree() in the return path.
>
> Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
> ---
You should write down the changelog ere. No idea what changed
from the previous version.
> security/keys/trusted-keys/trusted_tpm2.c | 23 +++++++++++++++++------
> 1 file changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
> index 0165da386289..8b7ab22950d1 100644
> --- a/security/keys/trusted-keys/trusted_tpm2.c
> +++ b/security/keys/trusted-keys/trusted_tpm2.c
> @@ -32,6 +32,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> struct trusted_key_options *options,
> u8 *src, u32 len)
> {
> + int err;
Declare as the last local variable (reverse christmas tree order).
Also, I'd use "int ret" since in other functions that is used.
> const int SCRATCH_SIZE = PAGE_SIZE;
> u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
> u8 *work = scratch, *work1;
> @@ -57,8 +58,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> unsigned char bool[3], *w = bool;
> /* tag 0 is emptyAuth */
> w = asn1_encode_boolean(w, w + sizeof(bool), true);
> - if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
> - return PTR_ERR(w);
> + if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) {
> + err = PTR_ERR(w);
> + goto out;
> + }
> work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
> }
>
> @@ -69,8 +72,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> * trigger, so if it does there's something nefarious going on
> */
> if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
> - "BUG: scratch buffer is too small"))
> - return -EINVAL;
> + "BUG: scratch buffer is too small")) {
> + err = -EINVAL;
> + goto out;
> + }
>
> work = asn1_encode_integer(work, end_work, options->keyhandle);
> work = asn1_encode_octet_string(work, end_work, pub, pub_len);
> @@ -79,10 +84,16 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> work1 = payload->blob;
> work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
> scratch, work - scratch);
> - if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
> - return PTR_ERR(work1);
> + if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) {
> + err = -EINVAL;
> + goto out;
Why you are changing the return value from PTR_ERR(work1
to -EINVAL?
> + }
> + kfree(scratch);
>
> return work1 - payload->blob;
> +
> +out:
Nit:
err:
It's only used for the error path.
> + return err;
> }
>
> struct tpm2_key_context {
> --
> 2.25.1
>
BR, Jarkko
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] KEYS: trusted: Fix memory leak in tpm2_key_encode()
2022-06-09 5:21 ` [PATCH v2] " Jarkko Sakkinen
@ 2022-06-09 5:22 ` Jarkko Sakkinen
0 siblings, 0 replies; 8+ messages in thread
From: Jarkko Sakkinen @ 2022-06-09 5:22 UTC (permalink / raw)
To: Jianglei Nie
Cc: jejb, zohar, dhowells, jmorris, serge, linux-integrity, keyrings,
linux-security-module, linux-kernel
On Thu, Jun 09, 2022 at 08:21:20AM +0300, Jarkko Sakkinen wrote:
> On Wed, Jun 08, 2022 at 09:17:32PM +0800, Jianglei Nie wrote:
> > tpm2_key_encode() allocates a memory chunk from scratch with kmalloc(),
> > but it is never freed, which leads to a memory leak. Free the memory
> > chunk with kfree() in the return path.
> >
> > Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
> > ---
>
> You should write down the changelog ere. No idea what changed
> from the previous version.
>
> > security/keys/trusted-keys/trusted_tpm2.c | 23 +++++++++++++++++------
> > 1 file changed, 17 insertions(+), 6 deletions(-)
> >
> > diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
> > index 0165da386289..8b7ab22950d1 100644
> > --- a/security/keys/trusted-keys/trusted_tpm2.c
> > +++ b/security/keys/trusted-keys/trusted_tpm2.c
> > @@ -32,6 +32,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> > struct trusted_key_options *options,
> > u8 *src, u32 len)
> > {
> > + int err;
>
> Declare as the last local variable (reverse christmas tree order).
>
> Also, I'd use "int ret" since in other functions that is used.
>
> > const int SCRATCH_SIZE = PAGE_SIZE;
> > u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
> > u8 *work = scratch, *work1;
> > @@ -57,8 +58,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> > unsigned char bool[3], *w = bool;
> > /* tag 0 is emptyAuth */
> > w = asn1_encode_boolean(w, w + sizeof(bool), true);
> > - if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
> > - return PTR_ERR(w);
> > + if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) {
> > + err = PTR_ERR(w);
> > + goto out;
> > + }
> > work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
> > }
> >
> > @@ -69,8 +72,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> > * trigger, so if it does there's something nefarious going on
> > */
> > if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
> > - "BUG: scratch buffer is too small"))
> > - return -EINVAL;
> > + "BUG: scratch buffer is too small")) {
> > + err = -EINVAL;
> > + goto out;
> > + }
> >
> > work = asn1_encode_integer(work, end_work, options->keyhandle);
> > work = asn1_encode_octet_string(work, end_work, pub, pub_len);
> > @@ -79,10 +84,16 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> > work1 = payload->blob;
> > work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
> > scratch, work - scratch);
> > - if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
> > - return PTR_ERR(work1);
> > + if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) {
> > + err = -EINVAL;
> > + goto out;
>
> Why you are changing the return value from PTR_ERR(work1
> to -EINVAL?
>
> > + }
> > + kfree(scratch);
> >
> > return work1 - payload->blob;
> > +
> > +out:
>
> Nit:
>
> err:
>
> It's only used for the error path.
>
> > + return err;
> > }
> >
> > struct tpm2_key_context {
> > --
> > 2.25.1
> >
>
> BR, Jarkko
And the patch is also missing fixes tag:
Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs")
BR, Jarkko
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] KEYS: trusted: Fix memory leak in tpm2_key_encode()
2022-06-08 13:38 ` Jonathan McDowell
@ 2022-06-09 5:28 ` jarkko
2022-07-22 8:21 ` [PATCH v3] " Jianglei Nie
0 siblings, 1 reply; 8+ messages in thread
From: jarkko @ 2022-06-09 5:28 UTC (permalink / raw)
To: Jonathan McDowell
Cc: Jianglei Nie, jejb, zohar, dhowells, jmorris, serge,
linux-integrity, keyrings, linux-security-module, linux-kernel
On Wed, Jun 08, 2022 at 01:38:35PM +0000, Jonathan McDowell wrote:
> On Wed, Jun 08, 2022 at 09:17:32PM +0800, Jianglei Nie wrote:
> > tpm2_key_encode() allocates a memory chunk from scratch with kmalloc(),
> > but it is never freed, which leads to a memory leak. Free the memory
> > chunk with kfree() in the return path.
>
> This change only does the kfree in the success path; "out" just returns
> the error without freeing the memory.
A valid point.
> > Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
> > ---
> > security/keys/trusted-keys/trusted_tpm2.c | 23 +++++++++++++++++------
> > 1 file changed, 17 insertions(+), 6 deletions(-)
> >
> > diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
> > index 0165da386289..8b7ab22950d1 100644
> > --- a/security/keys/trusted-keys/trusted_tpm2.c
> > +++ b/security/keys/trusted-keys/trusted_tpm2.c
> > @@ -32,6 +32,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> > struct trusted_key_options *options,
> > u8 *src, u32 len)
> > {
> > + int err;
> > const int SCRATCH_SIZE = PAGE_SIZE;
> > u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
Also, the fix is half-way there, it does not have OOM
check for scratch.
I.e. I'd change the declaration as:
u8 *scratch;
And later on after declarations:
scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
if (!scratch)
return -ENOMEM;
> > u8 *work = scratch, *work1;
> > @@ -57,8 +58,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> > unsigned char bool[3], *w = bool;
> > /* tag 0 is emptyAuth */
> > w = asn1_encode_boolean(w, w + sizeof(bool), true);
> > - if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
> > - return PTR_ERR(w);
> > + if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) {
> > + err = PTR_ERR(w);
> > + goto out;
> > + }
> > work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
> > }
> >
> > @@ -69,8 +72,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> > * trigger, so if it does there's something nefarious going on
> > */
> > if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
> > - "BUG: scratch buffer is too small"))
> > - return -EINVAL;
> > + "BUG: scratch buffer is too small")) {
> > + err = -EINVAL;
> > + goto out;
> > + }
> >
> > work = asn1_encode_integer(work, end_work, options->keyhandle);
> > work = asn1_encode_octet_string(work, end_work, pub, pub_len);
> > @@ -79,10 +84,16 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> > work1 = payload->blob;
> > work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
> > scratch, work - scratch);
> > - if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
> > - return PTR_ERR(work1);
> > + if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) {
> > + err = -EINVAL;
> > + goto out;
> > + }
> > + kfree(scratch);
> >
> > return work1 - payload->blob;
> > +
> > +out:
> > + return err;
I.e.
kfree(scratch);
return work1 - payload->blob;
err:
kfree(scratch);
return ret;
> > }
> >
> > struct tpm2_key_context {
> > --
> > 2.25.1
BR, Jarkko
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v3] KEYS: trusted: Fix memory leak in tpm2_key_encode()
2022-06-09 5:28 ` jarkko
@ 2022-07-22 8:21 ` Jianglei Nie
2022-07-28 8:07 ` Jarkko Sakkinen
0 siblings, 1 reply; 8+ messages in thread
From: Jianglei Nie @ 2022-07-22 8:21 UTC (permalink / raw)
To: jejb, jarkko, zohar, dhowells, jmorris, serge
Cc: linux-integrity, keyrings, linux-security-module, linux-kernel,
Jianglei Nie
tpm2_key_encode() allocates a memory chunk from scratch with kmalloc(),
but it is never freed, which leads to a memory leak. Free the memory
chunk with kfree() in the return path.
Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs")
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
---
security/keys/trusted-keys/trusted_tpm2.c | 33 ++++++++++++++++-------
1 file changed, 23 insertions(+), 10 deletions(-)
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 2b2c8eb258d5..eb25c784b5c3 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -32,8 +32,13 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
struct trusted_key_options *options,
u8 *src, u32 len)
{
+ int ret;
const int SCRATCH_SIZE = PAGE_SIZE;
- u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
+ u8 *scratch;
+
+ scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
+ if (!scratch)
+ return -ENOMEM;
u8 *work = scratch, *work1;
u8 *end_work = scratch + SCRATCH_SIZE;
u8 *priv, *pub;
@@ -47,9 +52,6 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
pub_len = get_unaligned_be16(src) + 2;
pub = src;
- if (!scratch)
- return -ENOMEM;
-
work = asn1_encode_oid(work, end_work, tpm2key_oid,
asn1_oid_len(tpm2key_oid));
@@ -57,8 +59,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
unsigned char bool[3], *w = bool;
/* tag 0 is emptyAuth */
w = asn1_encode_boolean(w, w + sizeof(bool), true);
- if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
- return PTR_ERR(w);
+ if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) {
+ ret = PTR_ERR(w);
+ goto err;
+ }
work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
}
@@ -69,8 +73,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
* trigger, so if it does there's something nefarious going on
*/
if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
- "BUG: scratch buffer is too small"))
- return -EINVAL;
+ "BUG: scratch buffer is too small")) {
+ ret = -EINVAL;
+ goto err;
+ }
work = asn1_encode_integer(work, end_work, options->keyhandle);
work = asn1_encode_octet_string(work, end_work, pub, pub_len);
@@ -79,10 +85,17 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
work1 = payload->blob;
work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
scratch, work - scratch);
- if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
- return PTR_ERR(work1);
+ if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) {
+ ret = PTR_ERR(work1);
+ goto err;
+ }
+ kfree(scratch);
return work1 - payload->blob;
+
+err:
+ kfree(scratch);
+ return ret;
}
struct tpm2_key_context {
--
2.25.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v3] KEYS: trusted: Fix memory leak in tpm2_key_encode()
2022-07-22 8:21 ` [PATCH v3] " Jianglei Nie
@ 2022-07-28 8:07 ` Jarkko Sakkinen
0 siblings, 0 replies; 8+ messages in thread
From: Jarkko Sakkinen @ 2022-07-28 8:07 UTC (permalink / raw)
To: Jianglei Nie
Cc: jejb, zohar, dhowells, jmorris, serge, linux-integrity, keyrings,
linux-security-module, linux-kernel
On Fri, Jul 22, 2022 at 04:21:25PM +0800, Jianglei Nie wrote:
> tpm2_key_encode() allocates a memory chunk from scratch with kmalloc(),
> but it is never freed, which leads to a memory leak. Free the memory
> chunk with kfree() in the return path.
>
> Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs")
> Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
> ---
The change log is missing. I have no idea what happened in v2 and v3.
> security/keys/trusted-keys/trusted_tpm2.c | 33 ++++++++++++++++-------
> 1 file changed, 23 insertions(+), 10 deletions(-)
>
> diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
> index 2b2c8eb258d5..eb25c784b5c3 100644
> --- a/security/keys/trusted-keys/trusted_tpm2.c
> +++ b/security/keys/trusted-keys/trusted_tpm2.c
> @@ -32,8 +32,13 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> struct trusted_key_options *options,
> u8 *src, u32 len)
> {
> + int ret;
> const int SCRATCH_SIZE = PAGE_SIZE;
> - u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
> + u8 *scratch;
> +
> + scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
> + if (!scratch)
> + return -ENOMEM;
> u8 *work = scratch, *work1;
> u8 *end_work = scratch + SCRATCH_SIZE;
> u8 *priv, *pub;
> @@ -47,9 +52,6 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> pub_len = get_unaligned_be16(src) + 2;
> pub = src;
>
> - if (!scratch)
> - return -ENOMEM;
> -
> work = asn1_encode_oid(work, end_work, tpm2key_oid,
> asn1_oid_len(tpm2key_oid));
>
> @@ -57,8 +59,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> unsigned char bool[3], *w = bool;
> /* tag 0 is emptyAuth */
> w = asn1_encode_boolean(w, w + sizeof(bool), true);
> - if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
> - return PTR_ERR(w);
> + if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) {
> + ret = PTR_ERR(w);
> + goto err;
> + }
> work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
> }
>
> @@ -69,8 +73,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> * trigger, so if it does there's something nefarious going on
> */
> if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
> - "BUG: scratch buffer is too small"))
> - return -EINVAL;
> + "BUG: scratch buffer is too small")) {
> + ret = -EINVAL;
> + goto err;
> + }
>
> work = asn1_encode_integer(work, end_work, options->keyhandle);
> work = asn1_encode_octet_string(work, end_work, pub, pub_len);
> @@ -79,10 +85,17 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
> work1 = payload->blob;
> work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
> scratch, work - scratch);
> - if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
> - return PTR_ERR(work1);
> + if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) {
> + ret = PTR_ERR(work1);
> + goto err;
> + }
>
> + kfree(scratch);
> return work1 - payload->blob;
> +
> +err:
> + kfree(scratch);
> + return ret;
> }
>
> struct tpm2_key_context {
> --
> 2.25.1
>
BR, Jarkko
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v2] KEYS: trusted: Fix memory leak in tpm2_key_encode()
@ 2022-06-08 14:35 Jianglei Nie
0 siblings, 0 replies; 8+ messages in thread
From: Jianglei Nie @ 2022-06-08 14:35 UTC (permalink / raw)
To: jejb, jarkko, zohar, dhowells, jmorris, serge
Cc: linux-integrity, keyrings, linux-security-module, linux-kernel,
Jianglei Nie
tpm2_key_encode() allocates a memory chunk from scratch with kmalloc(),
but it is never freed, which leads to a memory leak. Free the memory
chunk with kfree() in the return path.
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
---
security/keys/trusted-keys/trusted_tpm2.c | 24 +++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 0165da386289..6fd426212386 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -32,6 +32,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
struct trusted_key_options *options,
u8 *src, u32 len)
{
+ int err;
const int SCRATCH_SIZE = PAGE_SIZE;
u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
u8 *work = scratch, *work1;
@@ -57,8 +58,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
unsigned char bool[3], *w = bool;
/* tag 0 is emptyAuth */
w = asn1_encode_boolean(w, w + sizeof(bool), true);
- if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
- return PTR_ERR(w);
+ if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) {
+ err = PTR_ERR(w);
+ goto out;
+ }
work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
}
@@ -69,8 +72,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
* trigger, so if it does there's something nefarious going on
*/
if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
- "BUG: scratch buffer is too small"))
- return -EINVAL;
+ "BUG: scratch buffer is too small")) {
+ err = -EINVAL;
+ goto out;
+ }
work = asn1_encode_integer(work, end_work, options->keyhandle);
work = asn1_encode_octet_string(work, end_work, pub, pub_len);
@@ -79,10 +84,17 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
work1 = payload->blob;
work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
scratch, work - scratch);
- if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
- return PTR_ERR(work1);
+ if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) {
+ err = -EINVAL;
+ goto out;
+ }
+ kfree(scratch);
return work1 - payload->blob;
+
+out:
+ kfree(scratch);
+ return err;
}
struct tpm2_key_context {
--
2.25.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
end of thread, other threads:[~2022-07-28 8:07 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-08 13:17 [PATCH v2] KEYS: trusted: Fix memory leak in tpm2_key_encode() Jianglei Nie
2022-06-08 13:38 ` Jonathan McDowell
2022-06-09 5:28 ` jarkko
2022-07-22 8:21 ` [PATCH v3] " Jianglei Nie
2022-07-28 8:07 ` Jarkko Sakkinen
2022-06-09 5:21 ` [PATCH v2] " Jarkko Sakkinen
2022-06-09 5:22 ` Jarkko Sakkinen
2022-06-08 14:35 Jianglei Nie
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