syzbot


general protection fault in locks_remove_file
Status: fixed on 2020/10/09 08:34
Reported-by: syzbot+1bbb863a175d39474076@syzkaller.appspotmail.com
Fix commit: c5c6e00f6cc5 fix regression in "epoll: Keep a reference on files added to the check list"
First crash: 638d, last: 627d

Fix bisection: fixed by (bisect log) :
commit c5c6e00f6cc5d3ed0d6464b14e33f2f5c8505888
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed Sep 2 15:30:48 2020 +0000

  fix regression in "epoll: Keep a reference on files added to the check list"


Sample crash report:
kasan: CONFIG_KASAN_INLINE enabled
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 7933 Comm: syz-executor.5 Not tainted 4.14.196-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88809ff3e180 task.stack: ffff888084410000
RIP: 0010:locks_inode include/linux/fs.h:1060 [inline]
RIP: 0010:locks_remove_file+0x86/0x420 fs/locks.c:2563
RSP: 0018:ffff888084417d70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000000b RSI: 0000000000000001 RDI: 0000000000000058
RBP: ffff8880a5342040 R08: ffff8880aea2beb0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a53421d8
R13: ffff8880a53420bc R14: ffff88807ee37040 R15: ffff8880a5342050
FS:  0000000001dfb940(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001590004 CR3: 00000000a052c000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __fput+0x1ca/0x7a0 fs/file_table.c:202
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x416f01
RSP: 002b:00007ffd89375780 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000416f01
RDX: 0000000000000001 RSI: 00000000011902c0 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffd89375870 R11: 0000000000000293 R12: 00000000011902c0
R13: 000000000000a291 R14: ffffffffffffffff R15: 000000000118cfec
Code: 18 48 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 83 03 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5d 18 48 8d 7b 58 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 56 03 00 00 48 b8 00 00 00 00 00 fc ff df 48 
RIP: locks_inode include/linux/fs.h:1060 [inline] RSP: ffff888084417d70
RIP: locks_remove_file+0x86/0x420 fs/locks.c:2563 RSP: ffff888084417d70
general protection fault: 0000 [#2] PREEMPT SMP KASAN
Modules linked in:
---[ end trace 5881f116acba85f1 ]---
CPU: 1 PID: 7934 Comm: syz-executor.1 Tainted: G      D         4.14.196-syzkaller #0

Crashes (6):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/09/08 21:46 linux-4.14.y 2f166cdcf8a9 abf9ba4f .config log report syz
ci2-linux-4-14 2020/09/08 21:23 linux-4.14.y 2f166cdcf8a9 abf9ba4f .config log report syz
ci2-linux-4-14 2020/09/05 14:49 linux-4.14.y 2f166cdcf8a9 abf9ba4f .config log report syz
ci2-linux-4-14 2020/09/02 08:12 linux-4.14.y d7e78d08fa77 abf9ba4f .config log report syz
ci2-linux-4-14 2020/08/29 12:26 linux-4.14.y d7e78d08fa77 d5a3ae1f .config log report syz
ci2-linux-4-14 2020/08/28 19:56 linux-4.14.y d7e78d08fa77 d5a3ae1f .config log report syz