From: Ben Hutchings <ben@decadent.org.uk>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: akpm@linux-foundation.org, Denis Kirjanov <kda@linux-powerpc.org>,
"Vandana BN" <bnvandana@gmail.com>,
syzbot+66010012fd4c531a1a96@syzkaller.appspotmail.com,
"Mauro Carvalho Chehab" <mchehab+samsung@kernel.org>,
"Hans Verkuil" <hverkuil-cisco@xs4all.nl>
Subject: [PATCH 3.16 17/25] media: usb:zr364xx:Fix KASAN:null-ptr-deref Read in zr364xx_vidioc_querycap
Date: Tue, 12 Nov 2019 23:48:14 +0000 [thread overview]
Message-ID: <lsq.1573602477.179773981@decadent.org.uk> (raw)
In-Reply-To: <lsq.1573602477.548403712@decadent.org.uk>
3.16.77-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Vandana BN <bnvandana@gmail.com>
commit 5d2e73a5f80a5b5aff3caf1ec6d39b5b3f54b26e upstream.
SyzKaller hit the null pointer deref while reading from uninitialized
udev->product in zr364xx_vidioc_querycap().
==================================================================
BUG: KASAN: null-ptr-deref in read_word_at_a_time+0xe/0x20
include/linux/compiler.h:274
Read of size 1 at addr 0000000000000000 by task v4l_id/5287
CPU: 1 PID: 5287 Comm: v4l_id Not tainted 5.1.0-rc3-319004-g43151d6 #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xe8/0x16e lib/dump_stack.c:113
kasan_report.cold+0x5/0x3c mm/kasan/report.c:321
read_word_at_a_time+0xe/0x20 include/linux/compiler.h:274
strscpy+0x8a/0x280 lib/string.c:207
zr364xx_vidioc_querycap+0xb5/0x210 drivers/media/usb/zr364xx/zr364xx.c:706
v4l_querycap+0x12b/0x340 drivers/media/v4l2-core/v4l2-ioctl.c:1062
__video_do_ioctl+0x5bb/0xb40 drivers/media/v4l2-core/v4l2-ioctl.c:2874
video_usercopy+0x44e/0xf00 drivers/media/v4l2-core/v4l2-ioctl.c:3056
v4l2_ioctl+0x14e/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:364
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:509 [inline]
do_vfs_ioctl+0xced/0x12f0 fs/ioctl.c:696
ksys_ioctl+0xa0/0xc0 fs/ioctl.c:713
__do_sys_ioctl fs/ioctl.c:720 [inline]
__se_sys_ioctl fs/ioctl.c:718 [inline]
__x64_sys_ioctl+0x74/0xb0 fs/ioctl.c:718
do_syscall_64+0xcf/0x4f0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f3b56d8b347
Code: 90 90 90 48 8b 05 f1 fa 2a 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff
ff c3 90 90 90 90 90 90 90 90 90 90 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff
ff 73 01 c3 48 8b 0d c1 fa 2a 00 31 d2 48 29 c2 64
RSP: 002b:00007ffe005d5d68 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f3b56d8b347
RDX: 00007ffe005d5d70 RSI: 0000000080685600 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400884
R13: 00007ffe005d5ec0 R14: 0000000000000000 R15: 0000000000000000
==================================================================
For this device udev->product is not initialized and accessing it causes a NULL pointer deref.
The fix is to check for NULL before strscpy() and copy empty string, if
product is NULL
Reported-by: syzbot+66010012fd4c531a1a96@syzkaller.appspotmail.com
Signed-off-by: Vandana BN <bnvandana@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/media/usb/zr364xx/zr364xx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/media/usb/zr364xx/zr364xx.c
+++ b/drivers/media/usb/zr364xx/zr364xx.c
@@ -712,7 +712,8 @@ static int zr364xx_vidioc_querycap(struc
struct zr364xx_camera *cam = video_drvdata(file);
strlcpy(cap->driver, DRIVER_DESC, sizeof(cap->driver));
- strlcpy(cap->card, cam->udev->product, sizeof(cap->card));
+ if (cam->udev->product)
+ strlcpy(cap->card, cam->udev->product, sizeof(cap->card));
strlcpy(cap->bus_info, dev_name(&cam->udev->dev),
sizeof(cap->bus_info));
cap->device_caps = V4L2_CAP_VIDEO_CAPTURE |
next prev parent reply other threads:[~2019-11-12 23:51 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-12 23:47 [PATCH 3.16 00/25] 3.16.77-rc1 review Ben Hutchings
2019-11-12 23:47 ` [PATCH 3.16 01/25] KVM: Introduce kvm_get_arch_capabilities() Ben Hutchings
2019-11-12 23:47 ` [PATCH 3.16 02/25] KVM: x86: use Intel speculation bugs and features as derived in generic x86 code Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 03/25] x86/msr: Add the IA32_TSX_CTRL MSR Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 04/25] x86/cpu: Add a helper function x86_read_arch_cap_msr() Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 05/25] x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 06/25] x86/speculation/taa: Add mitigation for TSX Async Abort Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 07/25] x86/speculation/taa: Add sysfs reporting " Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 08/25] kvm/x86: Export MDS_NO=0 to guests when TSX is enabled Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 09/25] x86/tsx: Add "auto" option to the tsx= cmdline parameter Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 10/25] x86/speculation/taa: Add documentation for TSX Async Abort Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 11/25] x86/tsx: Add config options to set tsx=on|off|auto Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 12/25] x86/speculation/taa: Fix printing of TAA_MSG_SMT on IBRS_ALL CPUs Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 13/25] x86/bugs: Add ITLB_MULTIHIT bug infrastructure Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 14/25] drm/i915/gen8+: Add RC6 CTX corruption WA Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 15/25] net: netem: fix error path for corrupted GSO frames Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 16/25] ath6kl: fix a NULL-ptr-deref bug in ath6kl_usb_alloc_urb_from_pipe() Ben Hutchings
2019-11-12 23:48 ` Ben Hutchings [this message]
2019-11-12 23:48 ` [PATCH 3.16 18/25] media: technisat-usb2: break out of loop at end of buffer Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 19/25] ax25: enforce CAP_NET_RAW for raw sockets Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 20/25] ieee802154: " Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 21/25] appletalk: " Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 22/25] mISDN: " Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 23/25] nfc: " Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 24/25] cfg80211: wext: avoid copying malformed SSIDs Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 25/25] rtlwifi: Fix potential overflow on P2P code Ben Hutchings
2019-11-13 18:13 ` [PATCH 3.16 00/25] 3.16.77-rc1 review Guenter Roeck
2019-11-13 18:31 ` Ben Hutchings
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