BUG: corrupted list in fuse_dev_free

Status: fixed on 2020/10/03 15:51
Fix commit: c5c6e00f6cc5 fix regression in "epoll: Keep a reference on files added to the check list"
First crash: 1279d, last: 1279d
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"


Sample crash report:
NOHZ: local_softirq_pending 08
list_del corruption, ffff88809f1a1d28->next is LIST_POISON1 (dead000000000100)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:45!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 18670 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: ffff88809bd282c0 task.stack: ffff88809ff28000
RIP: 0010:__list_del_entry_valid.cold+0x23/0x55 lib/list_debug.c:45
RSP: 0018:ffff88809ff2fd18 EFLAGS: 00010282
RAX: 000000000000004e RBX: 1ffff11013fe5fb1 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff86ac12c0 RDI: ffffed1013fe5f99
RBP: ffff88809f1a1d28 R08: 000000000000004e R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dead000000000200
R13: dead000000000100 R14: ffff88809f1a1d30 R15: ffff88809f1a1cd0
FS:  00000000024e8940(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f774d002db8 CR3: 000000008b373000 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 include/linux/list.h:125 [inline]
 fuse_dev_free+0x57/0x1b0 fs/fuse/inode.c:1040
 fuse_dev_release+0x22a/0x320 fs/fuse/dev.c:2203
 __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: 0033:0x416f01
RSP: 002b:00007ffdb9aa7190 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000416f01
RDX: 0000000000000001 RSI: 00000000011903d8 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffdb9aa7280 R11: 0000000000000293 R12: 00000000011903d8
R13: 0000000000107121 R14: ffffffffffffffff R15: 000000000118cfec
Code: e6 e8 c8 9d 44 fe 0f 0b 48 89 ee 48 c7 c7 60 64 e4 86 e8 b7 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 
RIP: __list_del_entry_valid.cold+0x23/0x55 lib/list_debug.c:45 RSP: ffff88809ff2fd18
---[ end trace 356873dd61f3dd40 ]---

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/09/02 14:20 linux-4.14.y d7e78d08fa77 abf9ba4f .config console log report syz ci2-linux-4-14
* Struck through repros no longer work on HEAD.