WARNING in vb2_core_reqbufs

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 11743c56785c Merge tag 'rpmsg-v4.20' of git://github.com/a..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16680f9d400000
kernel config: https://syzkaller.appspot.com/x/.config?x=93932074d01b4a5
dashboard link: https://syzkaller.appspot.com/bug?extid=f9966a25169b6d66d61f
compiler: gcc (GCC) 8.0.1 20180413 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+f9966a...@syzkaller.appspotmail.com

WARNING: CPU: 0 PID: 24550 at
drivers/media/common/videobuf2/videobuf2-core.c:727
vb2_core_reqbufs+0x5c7/0x1040
drivers/media/common/videobuf2/videobuf2-core.c:727
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 24550 Comm: syz-executor0 Not tainted 4.19.0+ #311
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+0x244/0x39d lib/dump_stack.c:113
kobject: 'loop1' (00000000ed4787c1): kobject_uevent_env
panic+0x238/0x4e7 kernel/panic.c:184
__warn.cold.8+0x20/0x4a kernel/panic.c:536
report_bug+0x254/0x2d0 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:178 [inline]
do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:966
RIP: 0010:vb2_core_reqbufs+0x5c7/0x1040
drivers/media/common/videobuf2/videobuf2-core.c:727
Code: 83 c0 03 38 d0 7c 08 84 d2 0f 85 15 09 00 00 44 8b 3b 31 ff 48 83 c3
04 44 89 fe e8 03 47 34 fc 45 85 ff 75 9e e8 e9 45 34 fc <0f> 0b bb ea ff
ff ff e8 dd 45 34 fc 48 b8 00 00 00 00 00 fc ff df
RSP: 0018:ffff8801884ff538 EFLAGS: 00010212
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc9000ba50000
RDX: 00000000000000c3 RSI: ffffffff854b1e17 RDI: 0000000000000005
RBP: ffff8801884ff6d0 R08: ffff8801cb208240 R09: ffff8801cbba62b8
R10: ffffed0039774c5e R11: ffff8801cbba62f7 R12: 0000000000000008
R13: 0000000000000001 R14: ffff8801cbba6258 R15: ffff8801b88c8080
vb2_ioctl_reqbufs+0x1c2/0x350
drivers/media/common/videobuf2/videobuf2-v4l2.c:721
v4l_reqbufs+0xae/0xd0 drivers/media/v4l2-core/v4l2-ioctl.c:1882
__video_do_ioctl+0x519/0xf00 drivers/media/v4l2-core/v4l2-ioctl.c:2833
video_usercopy+0x5c1/0x1760 drivers/media/v4l2-core/v4l2-ioctl.c:3013
video_ioctl2+0x2c/0x33 drivers/media/v4l2-core/v4l2-ioctl.c:3057
v4l2_ioctl+0x154/0x1b0 drivers/media/v4l2-core/v4l2-dev.c:364
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
__do_sys_ioctl fs/ioctl.c:709 [inline]
__se_sys_ioctl fs/ioctl.c:707 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5481b79c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 0000000020000100 RSI: 00000000c0145608 RDI: 0000000000000003
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5481b7a6d4
R13: 00000000004c1cca R14: 00000000004d2bb8 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
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[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: 39ad1c1b6bb8 Add linux-next specific files for 20190129
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17971f17400000
kernel config: https://syzkaller.appspot.com/x/.config?x=a2b2e9c0bc43c14d
dashboard link: https://syzkaller.appspot.com/bug?extid=f9966a25169b6d66d61f
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1342c7a0c00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15a241c4c00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+f9966a...@syzkaller.appspotmail.com

WARNING: CPU: 1 PID: 8082 at
drivers/media/common/videobuf2/videobuf2-core.c:728
vb2_core_reqbufs+0x59b/0xf10
drivers/media/common/videobuf2/videobuf2-core.c:728

Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 8082 Comm: syz-executor505 Not tainted 5.0.0-rc4-next-20190129
#21

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+0x1db/0x2d0 lib/dump_stack.c:113
panic+0x2cb/0x65c kernel/panic.c:214
__warn.cold+0x20/0x48 kernel/panic.c:571
report_bug+0x263/0x2b0 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:178 [inline]
fixup_bug arch/x86/kernel/traps.c:173 [inline]
do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:290
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:vb2_core_reqbufs+0x59b/0xf10
drivers/media/common/videobuf2/videobuf2-core.c:728
Code: 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 56 08 00 00 45 8b 3c 9e 31
ff 44 89 fe e8 9f 41 3d fc 45 85 ff 75 9f e8 15 40 3d fc <0f> 0b 41 bc ea
ff ff ff e8 08 40 3d fc 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffff88809d8e7680 EFLAGS: 00010293
RAX: ffff88809138e3c0 RBX: 0000000000000000 RCX: ffffffff8544da11
RDX: 0000000000000000 RSI: ffffffff8544da1b RDI: 0000000000000005
RBP: ffff88809d8e77b0 R08: ffff88809138e3c0 R09: ffff88808d42d6f0
R10: ffffed1011a85ae5 R11: ffff88808d42d72f R12: 0000000000000001
R13: dffffc0000000000 R14: ffff88809d8e7728 R15: 0000000000000000
vb2_reqbufs drivers/media/common/videobuf2/videobuf2-v4l2.c:664 [inline]
vb2_reqbufs+0x1cb/0x210 drivers/media/common/videobuf2/videobuf2-v4l2.c:659
v4l2_m2m_reqbufs+0x90/0x1d0 drivers/media/v4l2-core/v4l2-mem2mem.c:457
v4l2_m2m_ioctl_reqbufs+0x6b/0x80
drivers/media/v4l2-core/v4l2-mem2mem.c:1051
v4l_reqbufs drivers/media/v4l2-core/v4l2-ioctl.c:1932 [inline]
v4l_reqbufs+0xad/0xe0 drivers/media/v4l2-core/v4l2-ioctl.c:1921
__video_do_ioctl+0x805/0xd80 drivers/media/v4l2-core/v4l2-ioctl.c:2872
video_usercopy+0x460/0x16b0 drivers/media/v4l2-core/v4l2-ioctl.c:3054
video_ioctl2+0x2d/0x35 drivers/media/v4l2-core/v4l2-ioctl.c:3098
v4l2_ioctl+0x156/0x1b0 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+0x107b/0x17d0 fs/ioctl.c:696
ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
__do_sys_ioctl fs/ioctl.c:720 [inline]
__se_sys_ioctl fs/ioctl.c:718 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440049
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7

48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff

ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc76fc9aa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440049
RDX: 0000000020000400 RSI: 00000000c0145608 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004018d0
R13: 0000000000401960 R14: 0000000000000000 R15: 0000000000000000

[syzbot]

syzbot has bisected this bug to:

commit 3b15f68e19c28a76d175f61943a8c23224afce93
Author: Dafna Hirschfeld <daf...@gmail.com>
Date: Mon Jan 21 11:46:18 2019 +0000

media: vicodec: Add support for resolution change event.

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1662bfbd200000
start commit: 3b15f68e media: vicodec: Add support for resolution change..
git tree: linux-next
final crash: https://syzkaller.appspot.com/x/report.txt?x=1562bfbd200000
console output: https://syzkaller.appspot.com/x/log.txt?x=1162bfbd200000

kernel config: https://syzkaller.appspot.com/x/.config?x=a2b2e9c0bc43c14d
dashboard link: https://syzkaller.appspot.com/bug?extid=f9966a25169b6d66d61f

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1342c7a0c00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15a241c4c00000

Reported-by: syzbot+f9966a...@syzkaller.appspotmail.com
Fixes: 3b15f68e19c2 ("media: vicodec: Add support for resolution change
event.")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[syzbot]

Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.