diff options
| author | Vandana BN <bnvandana@gmail.com> | 2019-05-22 04:34:15 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-23 08:19:34 +0100 |
| commit | 6ba34f5de2a45050729836e3d48ed10ee53d0276 (patch) | |
| tree | 00d775883560973bc9d3507ca171bc0fdd200168 /drivers/media | |
| parent | ca60f42d7965af9f22392caa4074ab0f58c7e1fe (diff) | |
media: usb:zr364xx:Fix KASAN:null-ptr-deref Read in zr364xx_vidioc_querycap
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 4.9: This function uses strlcpy() instead of strscpy()]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/usb/zr364xx/zr364xx.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/media/usb/zr364xx/zr364xx.c b/drivers/media/usb/zr364xx/zr364xx.c index e3735bfcc02f..c5513f55e64e 100644 --- a/drivers/media/usb/zr364xx/zr364xx.c +++ b/drivers/media/usb/zr364xx/zr364xx.c @@ -711,7 +711,8 @@ static int zr364xx_vidioc_querycap(struct file *file, void *priv, 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 | |