From: Jiri Slaby <jslaby@suse.cz>
To: stable@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
David Howells <dhowells@redhat.com>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
linux-ima-devel@lists.sourceforge.net,
James Morris <james.l.morris@oracle.com>,
Jiri Slaby <jslaby@suse.cz>
Subject: [PATCH 3.12 18/38] mpi: Fix NULL ptr dereference in mpi_powm() [ver #3]
Date: Tue, 13 Dec 2016 20:52:44 +0100 [thread overview]
Message-ID: <18fb7a8fb3d55275fc17f4ff5c7e34dd2b6d74e5.1481658746.git.jslaby@suse.cz> (raw)
In-Reply-To: <15034b96ec06ee859b67c6cd4e3be569a4ef286b.1481658746.git.jslaby@suse.cz>
In-Reply-To: <cover.1481658746.git.jslaby@suse.cz>
From: Andrey Ryabinin <aryabinin@virtuozzo.com>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit f5527fffff3f002b0a6b376163613b82f69de073 upstream.
This fixes CVE-2016-8650.
If mpi_powm() is given a zero exponent, it wants to immediately return
either 1 or 0, depending on the modulus. However, if the result was
initalised with zero limb space, no limbs space is allocated and a
NULL-pointer exception ensues.
Fix this by allocating a minimal amount of limb space for the result when
the 0-exponent case when the result is 1 and not touching the limb space
when the result is 0.
This affects the use of RSA keys and X.509 certificates that carry them.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
PGD 0
Oops: 0002 [#1] SMP
Modules linked in:
CPU: 3 PID: 3014 Comm: keyctl Not tainted 4.9.0-rc6-fscache+ #278
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
task: ffff8804011944c0 task.stack: ffff880401294000
RIP: 0010:[<ffffffff8138ce5d>] [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
RSP: 0018:ffff880401297ad8 EFLAGS: 00010212
RAX: 0000000000000000 RBX: ffff88040868bec0 RCX: ffff88040868bba0
RDX: ffff88040868b260 RSI: ffff88040868bec0 RDI: ffff88040868bee0
RBP: ffff880401297ba8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000047 R11: ffffffff8183b210 R12: 0000000000000000
R13: ffff8804087c7600 R14: 000000000000001f R15: ffff880401297c50
FS: 00007f7a7918c700(0000) GS:ffff88041fb80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000401250000 CR4: 00000000001406e0
Stack:
ffff88040868bec0 0000000000000020 ffff880401297b00 ffffffff81376cd4
0000000000000100 ffff880401297b10 ffffffff81376d12 ffff880401297b30
ffffffff81376f37 0000000000000100 0000000000000000 ffff880401297ba8
Call Trace:
[<ffffffff81376cd4>] ? __sg_page_iter_next+0x43/0x66
[<ffffffff81376d12>] ? sg_miter_get_next_page+0x1b/0x5d
[<ffffffff81376f37>] ? sg_miter_next+0x17/0xbd
[<ffffffff8138ba3a>] ? mpi_read_raw_from_sgl+0xf2/0x146
[<ffffffff8132a95c>] rsa_verify+0x9d/0xee
[<ffffffff8132acca>] ? pkcs1pad_sg_set_buf+0x2e/0xbb
[<ffffffff8132af40>] pkcs1pad_verify+0xc0/0xe1
[<ffffffff8133cb5e>] public_key_verify_signature+0x1b0/0x228
[<ffffffff8133d974>] x509_check_for_self_signed+0xa1/0xc4
[<ffffffff8133cdde>] x509_cert_parse+0x167/0x1a1
[<ffffffff8133d609>] x509_key_preparse+0x21/0x1a1
[<ffffffff8133c3d7>] asymmetric_key_preparse+0x34/0x61
[<ffffffff812fc9f3>] key_create_or_update+0x145/0x399
[<ffffffff812fe227>] SyS_add_key+0x154/0x19e
[<ffffffff81001c2b>] do_syscall_64+0x80/0x191
[<ffffffff816825e4>] entry_SYSCALL64_slow_path+0x25/0x25
Code: 56 41 55 41 54 53 48 81 ec a8 00 00 00 44 8b 71 04 8b 42 04 4c 8b 67 18 45 85 f6 89 45 80 0f 84 b4 06 00 00 85 c0 75 2f 41 ff ce <49> c7 04 24 01 00 00 00 b0 01 75 0b 48 8b 41 18 48 83 38 01 0f
RIP [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
RSP <ffff880401297ad8>
CR2: 0000000000000000
---[ end trace d82015255d4a5d8d ]---
Basically, this is a backport of a libgcrypt patch:
http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=patch;h=6e1adb05d290aeeb1c230c763970695f4a538526
Fixes: cdec9cb5167a ("crypto: GnuPG based MPI lib - source files (part 1)")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
cc: linux-ima-devel@lists.sourceforge.net
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
lib/mpi/mpi-pow.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/lib/mpi/mpi-pow.c b/lib/mpi/mpi-pow.c
index 5464c8744ea9..e24388a863a7 100644
--- a/lib/mpi/mpi-pow.c
+++ b/lib/mpi/mpi-pow.c
@@ -64,8 +64,13 @@ int mpi_powm(MPI res, MPI base, MPI exp, MPI mod)
if (!esize) {
/* Exponent is zero, result is 1 mod MOD, i.e., 1 or 0
* depending on if MOD equals 1. */
- rp[0] = 1;
res->nlimbs = (msize == 1 && mod->d[0] == 1) ? 0 : 1;
+ if (res->nlimbs) {
+ if (mpi_resize(res, 1) < 0)
+ goto enomem;
+ rp = res->d;
+ rp[0] = 1;
+ }
res->sign = 0;
goto leave;
}
--
2.11.0
next prev parent reply other threads:[~2016-12-13 19:59 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20161213195251epcas5p33cd25dd883c71a35fd9cdec0b8e8254a@epcas5p3.samsung.com>
2016-12-13 19:52 ` [PATCH 3.12 00/38] 3.12.69-stable review Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 01/38] x86/idle: Restore trace_cpu_idle to mwait_idle() calls Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 02/38] PCI: Fix devfn for VPD access through function 0 Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 03/38] PCI: Use function 0 VPD for identical functions, regular VPD for others Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 04/38] i2c: at91: fix write transfers by clearing pending interrupt first Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 05/38] mtd: blkdevs: fix potential deadlock + lockdep warnings Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 06/38] kernel/panic.c: turn off locks debug before releasing console lock Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 07/38] tty: audit: Fix audit source Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 08/38] Revert "drivers/net: Disable UFO through virtio" Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 09/38] KVM: x86: drop error recovery in em_jmp_far and em_ret_far Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 10/38] usb: chipidea: move the lock initialization to core file Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 11/38] USB: serial: cp210x: add ID for the Zone DPMX Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 12/38] USB: serial: ftdi_sio: add support for TI CC3200 LaunchPad Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 13/38] Fix USB CB/CBI storage devices with CONFIG_VMAP_STACK=y Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 14/38] scsi: mpt3sas: Fix secure erase premature termination Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 15/38] tile: avoid using clocksource_cyc2ns with absolute cycle count Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 16/38] cfg80211: limit scan results cache size Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 17/38] apparmor: fix change_hat not finding hat after policy replacement Jiri Slaby
2016-12-13 19:52 ` Jiri Slaby [this message]
2016-12-13 19:52 ` [PATCH 3.12 19/38] drm/radeon: Ensure vblank interrupt is enabled on DPMS transition to on Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 20/38] x86/traps: Ignore high word of regs->cs in early_fixup_exception() Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 21/38] rcu: Fix soft lockup for rcu_nocb_kthread Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 22/38] PCI: Export pcie_find_root_port Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 23/38] mwifiex: printk() overflow with 32-byte SSIDs Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 24/38] pwm: Fix device reference leak Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 25/38] ipv6: Set skb->protocol properly for local output Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 26/38] ipv4: " Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 27/38] ALSA: pcm : Call kill_fasync() in stream lock Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 28/38] ip6_tunnel: disable caching when the traffic class is inherited Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 29/38] net: sky2: Fix shutdown crash Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 30/38] l2tp: fix racy SOCK_ZAPPED flag check in l2tp_ip{,6}_bind() Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 31/38] net/sched: pedit: make sure that offset is valid Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 32/38] net/dccp: fix use-after-free in dccp_invalid_packet Jiri Slaby
2016-12-13 19:52 ` [PATCH 3.12 33/38] packet: fix race condition in packet_set_ring Jiri Slaby
2016-12-13 19:53 ` [PATCH 3.12 34/38] net: avoid signed overflows for SO_{SND|RCV}BUFFORCE Jiri Slaby
2016-12-13 19:53 ` [PATCH 3.12 35/38] net: ping: check minimum size on ICMP header length Jiri Slaby
2016-12-13 19:53 ` [PATCH 3.12 36/38] sparc32: Fix inverted invalid_frame_pointer checks on sigreturns Jiri Slaby
2016-12-13 19:53 ` [PATCH 3.12 37/38] sparc64: Fix find_node warning if numa node cannot be found Jiri Slaby
2016-12-13 19:53 ` [PATCH 3.12 38/38] sparc64: fix compile warning section mismatch in find_node() Jiri Slaby
2016-12-14 0:51 ` [PATCH 3.12 00/38] 3.12.69-stable review Shuah Khan
2016-12-17 9:10 ` Jiri Slaby
2016-12-14 3:42 ` Guenter Roeck
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