Re: general protection fault in __vb2_queue_free

From: syzbot
Date: Tue Oct 30 2018 - 16:40:15 EST

syzbot has found a reproducer for 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=14c8eb5b400000
kernel config: https://syzkaller.appspot.com/x/.config?x=93932074d01b4a5
dashboard link: https://syzkaller.appspot.com/bug?extid=e1fb118a2ebb88031d21
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=158fdbcb400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11d7d06d400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+e1fb118a2ebb88031d21@xxxxxxxxxxxxxxxxxxxxxxxxx

audit: type=1800 audit(1540931695.249:30): pid=5573 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 5728 Comm: syz-executor006 Not tainted 4.19.0+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:vb2_vmalloc_put_userptr+0x73/0x250 drivers/media/common/videobuf2/videobuf2-vmalloc.c:136
Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 c2 01 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 5e 08 48 8d 7b 09 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 72 01 00 00
RSP: 0018:ffff8801d2d77408 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffffffff113e0ac
RDX: 0000000000000001 RSI: ffffffff854c11d9 RDI: 0000000000000009
RBP: ffff8801d2d77438 R08: ffff8801d4b246c0 R09: ffffed003a5d044e
R10: ffff8801d2d77530 R11: ffff8801d2e82277 R12: ffffc90002551000
R13: 0000000000000000 R14: ffff8801cec5f380 R15: ffff8801cec5f380
FS: 0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000043e910 CR3: 000000000946a000 CR4: 00000000001406f0
Call Trace:
__vb2_buf_userptr_put drivers/media/common/videobuf2/videobuf2-core.c:258 [inline]
__vb2_free_mem drivers/media/common/videobuf2/videobuf2-core.c:415 [inline]
__vb2_queue_free+0x4b1/0xa30 drivers/media/common/videobuf2/videobuf2-core.c:456
vb2_core_queue_release+0x62/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2055
vb2_queue_release+0x15/0x20 drivers/media/common/videobuf2/videobuf2-v4l2.c:672
v4l2_m2m_ctx_release+0x1e/0x35 drivers/media/v4l2-core/v4l2-mem2mem.c:927
vicodec_release+0xbd/0x120 drivers/media/platform/vicodec/vicodec-core.c:1236
v4l2_release+0xfb/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448
__fput+0x385/0xa30 fs/file_table.c:278
____fput+0x15/0x20 fs/file_table.c:309
task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x1ad6/0x26d0 kernel/exit.c:867
do_group_exit+0x177/0x440 kernel/exit.c:970
__do_sys_exit_group kernel/exit.c:981 [inline]
__se_sys_exit_group kernel/exit.c:979 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x442d98
Code: Bad RIP value.
RSP: 002b:00007ffc32d53f78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442d98
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004c2968 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d4180 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 894fb90190094ea9 ]---
RIP: 0010:vb2_vmalloc_put_userptr+0x73/0x250 drivers/media/common/videobuf2/videobuf2-vmalloc.c:136
Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 c2 01 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 5e 08 48 8d 7b 09 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 72 01 00 00
RSP: 0018:ffff8801d2d77408 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffffffff113e0ac
RDX: 0000000000000001 RSI: ffffffff854c11d9 RDI: 0000000000000009
RBP: ffff8801d2d77438 R08: ffff8801d4b246c0 R09: ffffed003a5d044e
R10: ffff8801d2d77530 R11: ffff8801d2e82277 R12: ffffc90002551000
R13: 0000000000000000 R14: ffff8801cec5f380 R15: ffff8801cec5f380
FS: 000000000073c880(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000442d6e CR3: 000000000946a000 CR4: 00000000001406f0