media: vivid:add sanity check to avoid divide error and set value to 1 if 0.
Syzbot reported divide error in vivid_thread_vid_cap, which has been
seen only once and does not have a reproducer.
This patch adds sanity checks for the
denominator value with WARN_ON if it is 0 and replaces it with 1.
divide error: 0000 [#1] PREEMPT SMP KASAN
kobject: 'tx-0' (
0000000017161f7f): kobject_uevent_env
CPU: 0 PID: 23689 Comm: vivid-003-vid-c Not tainted 5.0.0-rc4+ #58
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:vivid_cap_update_frame_period
drivers/media/platform/vivid/vivid-kthread-cap.c:661 [inline]
RIP: 0010:vivid_thread_vid_cap+0x221/0x284
drivers/media/platform/vivid/vivid-kthread-cap.c:789
Code: 48 c1 e9 03 0f b6 0c 11 48 89 f2 48 69 c0 00 ca 9a 3b 83 c2 03 38
ca
7c 08 84 c9 0f 85 f0 1e 00 00 41 8b 8f 24 64 00 00 31 d2 <48> f7 f1 49
89
c4 48 89 c3 49 8d 87 28 64 00 00 48 89 c2 48 89 45
RSP: 0018:
ffff88808b4afd68 EFLAGS:
00010246
kobject: 'tx-0' (
0000000017161f7f): fill_kobj_path: path
= '/devices/virtual/net/gre0/queues/tx-0'
RAX:
000000de5a6f8e00 RBX:
0000000100047b22 RCX:
0000000000000000
RDX:
0000000000000000 RSI:
0000000000000004 RDI:
0000000000000004
RBP:
ffff88808b4aff00 R08:
ffff88804862e1c0 R09:
ffffffff89997008
R10:
ffffffff89997010 R11:
0000000000000001 R12:
00000000fffffffc
R13:
ffff8880a17e0500 R14:
ffff88803e40f760 R15:
ffff8882182b0140
FS:
0000000000000000(0000) GS:
ffff8880ae800000(0000)
knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
00000000004cdc90 CR3:
000000005d827000 CR4:
00000000001426f0
Call Trace:
kobject: 'gretap0' (
00000000d7549098): kobject_add_internal: parent:
'net',
set: 'devices'
kobject: 'loop2' (
0000000094ed4ee4): kobject_uevent_env
kobject: 'loop2' (
0000000094ed4ee4): fill_kobj_path: path
= '/devices/virtual/block/loop2'
kthread+0x357/0x430 kernel/kthread.c:246
kobject: 'gretap0' (
00000000d7549098): kobject_uevent_env
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Modules linked in:
kobject: 'gretap0' (
00000000d7549098): fill_kobj_path: path
= '/devices/virtual/net/gretap0'
---[ end trace
bc5c8b25b64d768f ]---
kobject: 'loop1' (
0000000032036b86): kobject_uevent_env
RIP: 0010:vivid_cap_update_frame_period
drivers/media/platform/vivid/vivid-kthread-cap.c:661 [inline]
RIP: 0010:vivid_thread_vid_cap+0x221/0x2840
drivers/media/platform/vivid/vivid-kthread-cap.c:789
kobject: 'loop1' (
0000000032036b86): fill_kobj_path: path
= '/devices/virtual/block/loop1'
Code: 48 c1 e9 03 0f b6 0c 11 48 89 f2 48 69 c0 00 ca 9a 3b 83 c2 03 38
ca
7c 08 84 c9 0f 85 f0 1e 00 00 41 8b 8f 24 64 00 00 31 d2 <48> f7 f1 49
89
c4 48 89 c3 49 8d 87 28 64 00 00 48 89 c2 48 89 45
kobject: 'loop0' (
00000000dd9927c3): kobject_uevent_env
RSP: 0018:
ffff88808b4afd68 EFLAGS:
00010246
RAX:
000000de5a6f8e00 RBX:
0000000100047b22 RCX:
0000000000000000
kobject: 'queues' (
000000007ed20666): kobject_add_internal:
parent: 'gretap0', set: '<NULL>'
RDX:
0000000000000000 RSI:
0000000000000004 RDI:
0000000000000004
RBP:
ffff88808b4aff00 R08:
ffff88804862e1c0 R09:
ffffffff89997008
kobject: 'loop0' (
00000000dd9927c3): fill_kobj_path: path
= '/devices/virtual/block/loop0'
R10:
ffffffff89997010 R11:
0000000000000001 R12:
00000000fffffffc
kobject: 'queues' (
000000007ed20666): kobject_uevent_env
R13:
ffff8880a17e0500 R14:
ffff88803e40f760 R15:
ffff8882182b0140
FS:
0000000000000000(0000) GS:
ffff8880ae800000(0000)
knlGS:
0000000000000000
kobject: 'loop5' (
00000000a41f9e79): kobject_uevent_env
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
kobject: 'queues' (
000000007ed20666): kobject_uevent_env: filter
function
caused the event to drop!
CR2:
00000000004cdc90 CR3:
000000005d827000 CR4:
00000000001426f0
kobject: 'loop5' (
00000000a41f9e79): fill_kobj_path: path
= '/devices/virtual/block/loop5'
Reported-by: syz...@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>