BUG: corrupted list in mousedev_release

Status: fixed on 2020/09/30 06:39
Fix commit: c5c6e00f6cc5 fix regression in "epoll: Keep a reference on files added to the check list"
First crash: 826d, last: 826d

Fix bisection: fixed by (bisect log) :
commit c5c6e00f6cc5d3ed0d6464b14e33f2f5c8505888
Author: Al Viro <>
Date: Wed Sep 2 15:30:48 2020 +0000

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

similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 BUG: corrupted list in mousedev_release syz done 1 825d 825d 1/1 fixed on 2020/09/30 06:27
upstream BUG: corrupted list in mousedev_release syz done 5 824d 825d 17/24 fixed on 2020/09/25 01:17

Sample crash report:
IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready
Bluetooth: hci0 command 0x0409 tx timeout
Bluetooth: hci0 command 0x041b tx timeout
list_del corruption, ffff8880a95f52d0->prev is LIST_POISON2 (dead000000000200)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:48!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 7852 Comm: syz-executor.0 Not tainted 4.14.195-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a7f98000 task.stack: ffff888090ce0000
RIP: 0010:__list_del_entry_valid.cold+0x37/0x55 lib/list_debug.c:48
RSP: 0018:ffff888090ce7da8 EFLAGS: 00010286
RAX: 000000000000004e RBX: ffff88809bfe9100 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff86ac12c0 RDI: ffffed101219cfab
RBP: ffff8880a95f52d0 R08: 000000000000004e R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dead000000000200
R13: ffff88809bfe9198 R14: ffff8880a95f52d0 R15: ffff8880931a6ad0
FS:  00007fa08283f700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005563da6b2457 CR3: 00000000a4fe7000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __list_del_entry include/linux/list.h:117 [inline]
 list_del_rcu include/linux/rculist.h:130 [inline]
 mousedev_detach_client drivers/input/mousedev.c:518 [inline]
 mousedev_release+0x7d/0x1e0 drivers/input/mousedev.c:528
 __fput+0x25f/0x7a0 fs/file_table.c:210
 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
RIP: 0033:0x45d5b9
RSP: 002b:00007fa08283ec78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9
RAX: 0000000000000000 RBX: 0000000000002ac0 RCX: 000000000045d5b9
RDX: 0000000000000004 RSI: 0000000000000001 RDI: 0000000000000005
RBP: 000000000118cf88 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000040 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffc03acbd6f R14: 00007fa08283f9c0 R15: 000000000118cf4c
Code: 9d 44 fe 0f 0b 4c 89 ea 48 89 ee 48 c7 c7 a0 63 e4 86 e8 a3 9d 44 fe 0f 0b 4c 89 e2 48 89 ee 48 c7 c7 00 64 e4 86 e8 8f 9d 44 fe <0f> 0b 48 89 ee 48 c7 c7 c0 64 e4 86 e8 7e 9d 44 fe 0f 0b 90 90 
RIP: __list_del_entry_valid.cold+0x37/0x55 lib/list_debug.c:48 RSP: ffff888090ce7da8
---[ end trace e4bd25da27820950 ]---

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/08/30 16:27 linux-4.14.y d7e78d08fa77 d5a3ae1f .config log report syz
* Struck through repros no longer work on HEAD.