syzbot


general protection fault in fuse_dev_release

Status: moderation: reported on 2026/04/22 04:24
Subsystems: fuse
[Documentation on labels]
Reported-by: syzbot+55dd926b8319c22f1a2f@syzkaller.appspotmail.com
First crash: 10d, last: 10d
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: unable to handle kernel NULL pointer dereference in fuse_dev_release fuse 10 1 1208d 1204d 0/29 auto-obsoleted due to no activity on 2023/04/05 16:12

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 8396 Comm: syz.4.878 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:list_empty include/linux/list.h:381 [inline]
RIP: 0010:list_splice_init include/linux/list.h:579 [inline]
RIP: 0010:fuse_dev_release+0x19c/0x670 fs/fuse/dev.c:2232
Code: 5c 24 28 48 8b 44 24 30 42 80 3c 38 00 74 08 48 89 df e8 f7 cd ec fe 48 8b 0b 48 89 4c 24 18 4e 8d 24 31 4d 89 e5 49 c1 ed 03 <43> 80 7c 3d 00 00 74 08 4c 89 e7 e8 d4 cd ec fe 4d 8b 3c 24 4d 39
RSP: 0018:ffffc90010dc7ca0 EFLAGS: 00010246
RAX: 1ffff11005543873 RBX: ffff88802aa1c398 RCX: 0000000000000000
RDX: ffffc9000fa4f000 RSI: 0000000000000031 RDI: 0000000000000032
RBP: ffffc90010dc7d80 R08: ffffffff8b38b760 R09: ffffffff8dfc8100
R10: dffffc0000000000 R11: fffffbfff1f1a83f R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007f6e760056c0(0000) GS:ffff888125eba000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e76004ff8 CR3: 000000003e544000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __fput+0x461/0xa70 fs/file_table.c:510
 fput_close_sync+0x11f/0x240 fs/file_table.c:615
 __do_sys_close fs/open.c:1507 [inline]
 __se_sys_close fs/open.c:1492 [inline]
 __x64_sys_close+0x7e/0x110 fs/open.c:1492
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6e77dcc819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6e76005028 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f6e78046090 RCX: 00007f6e77dcc819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f6e77e62c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6e78046128 R14: 00007f6e78046090 R15: 00007ffe88e13f98
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:list_empty include/linux/list.h:381 [inline]
RIP: 0010:list_splice_init include/linux/list.h:579 [inline]
RIP: 0010:fuse_dev_release+0x19c/0x670 fs/fuse/dev.c:2232
Code: 5c 24 28 48 8b 44 24 30 42 80 3c 38 00 74 08 48 89 df e8 f7 cd ec fe 48 8b 0b 48 89 4c 24 18 4e 8d 24 31 4d 89 e5 49 c1 ed 03 <43> 80 7c 3d 00 00 74 08 4c 89 e7 e8 d4 cd ec fe 4d 8b 3c 24 4d 39
RSP: 0018:ffffc90010dc7ca0 EFLAGS: 00010246
RAX: 1ffff11005543873 RBX: ffff88802aa1c398 RCX: 0000000000000000
RDX: ffffc9000fa4f000 RSI: 0000000000000031 RDI: 0000000000000032
RBP: ffffc90010dc7d80 R08: ffffffff8b38b760 R09: ffffffff8dfc8100
R10: dffffc0000000000 R11: fffffbfff1f1a83f R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007f6e760056c0(0000) GS:ffff888125eba000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e76004ff8 CR3: 000000003e544000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	5c                   	pop    %rsp
   1:	24 28                	and    $0x28,%al
   3:	48 8b 44 24 30       	mov    0x30(%rsp),%rax
   8:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1)
   d:	74 08                	je     0x17
   f:	48 89 df             	mov    %rbx,%rdi
  12:	e8 f7 cd ec fe       	call   0xfeecce0e
  17:	48 8b 0b             	mov    (%rbx),%rcx
  1a:	48 89 4c 24 18       	mov    %rcx,0x18(%rsp)
  1f:	4e 8d 24 31          	lea    (%rcx,%r14,1),%r12
  23:	4d 89 e5             	mov    %r12,%r13
  26:	49 c1 ed 03          	shr    $0x3,%r13
* 2a:	43 80 7c 3d 00 00    	cmpb   $0x0,0x0(%r13,%r15,1) <-- trapping instruction
  30:	74 08                	je     0x3a
  32:	4c 89 e7             	mov    %r12,%rdi
  35:	e8 d4 cd ec fe       	call   0xfeecce0e
  3a:	4d 8b 3c 24          	mov    (%r12),%r15
  3e:	4d                   	rex.WRB
  3f:	39                   	.byte 0x39

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/18 04:15 linux-next c7275b05bc42 5be7a9de .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in fuse_dev_release
* Struck through repros no longer work on HEAD.