Hello,
syzbot found the following crash on:
HEAD commit: b94ae8ad Merge tag 'seccomp-v5.5-rc1' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1387ab12e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=ff560c3de405258c
dashboard link: https://syzkaller.appspot.com/bug?extid=d37abaade33a934f16f2
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12945c41e00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=161e202ee00000
The bug was bisected to:
commit 8cefc107ca54c8b06438b7dc9cc08bc0a11d5b98
Author: David Howells <dhowells@xxxxxxxxxx>
Date: Fri Nov 15 13:30:32 2019 +0000
pipe: Use head and tail pointers for the ring, not cursor and length
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=118cce96e00000
final crash: https://syzkaller.appspot.com/x/report.txt?x=138cce96e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=158cce96e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d37abaade33a934f16f2@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 8cefc107ca54 ("pipe: Use head and tail pointers for the ring, not
cursor and length")
------------[ cut here ]------------
kernel BUG at fs/pipe.c:582!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9433 Comm: syz-executor802 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:pipe_poll+0x37f/0x400 fs/pipe.c:582
Code: ff 85 db 75 09 e8 b1 ee b5 ff 41 83 ce 08 e8 a8 ee b5 ff 44 89 f0 48
83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 91 ee b5 ff <0f> 0b e8 ca 40
f3 ff e9 ed fc ff ff e8 c0 40 f3 ff e9 b3 fd ff ff
RSP: 0018:ffff888093e3f698 EFLAGS: 00010293
RAX: ffff8880a96083c0 RBX: ffff88809af6e800 RCX: ffffffff81beed8a
RDX: 0000000000000000 RSI: ffffffff81beefaf RDI: 0000000000000004
RBP: ffff888093e3f6d0 R08: ffff8880a96083c0 R09: ffff8880a9608c50
R10: fffffbfff146e220 R11: ffffffff8a371107 R12: ffff88809c770d40
R13: 00000000fffffffa R14: 0000000000000010 R15: 00000000000001f6
FS: 00007fc5aa3cb700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020200000 CR3: 000000009b5a1000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
vfs_poll include/linux/poll.h:90 [inline]
do_select+0x922/0x16f0 fs/select.c:534
core_sys_select+0x53c/0x8c0 fs/select.c:677
do_pselect.constprop.0+0x199/0x1e0 fs/select.c:759
__do_sys_pselect6 fs/select.c:784 [inline]
__se_sys_pselect6 fs/select.c:769 [inline]
__x64_sys_pselect6+0x1fc/0x2e0 fs/select.c:769
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x44a629
Code: e8 5c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 2b cc fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc5aa3cada8 EFLAGS: 00000246 ORIG_RAX: 000000000000010e
RAX: ffffffffffffffda RBX: 00000000006dbc38 RCX: 000000000044a629
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000040
RBP: 00000000006dbc30 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000140 R11: 0000000000000246 R12: 00000000006dbc3c
R13: 00007fffcaf6d1bf R14: 00007fc5aa3cb9c0 R15: 20c49ba5e353f7cf
Modules linked in:
---[ end trace 1c441dd64ff48137 ]---
RIP: 0010:pipe_poll+0x37f/0x400 fs/pipe.c:582
Code: ff 85 db 75 09 e8 b1 ee b5 ff 41 83 ce 08 e8 a8 ee b5 ff 44 89 f0 48
83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 91 ee b5 ff <0f> 0b e8 ca 40
f3 ff e9 ed fc ff ff e8 c0 40 f3 ff e9 b3 fd ff ff
RSP: 0018:ffff888093e3f698 EFLAGS: 00010293
RAX: ffff8880a96083c0 RBX: ffff88809af6e800 RCX: ffffffff81beed8a
RDX: 0000000000000000 RSI: ffffffff81beefaf RDI: 0000000000000004
RBP: ffff888093e3f6d0 R08: ffff8880a96083c0 R09: ffff8880a9608c50
R10: fffffbfff146e220 R11: ffffffff8a371107 R12: ffff88809c770d40
R13: 00000000fffffffa R14: 0000000000000010 R15: 00000000000001f6
FS: 00007fc5aa3cb700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020200000 CR3: 000000009b5a1000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
This bug is generated by a bot. It may contain errors.
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
