syzbot


INFO: task hung in fuse_simple_request

Status: auto-obsoleted due to no activity on 2024/02/03 13:59
Reported-by: syzbot+8b80be47d93784f776de@syzkaller.appspotmail.com
First crash: 313d, last: 215d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in fuse_simple_request fuse C inconclusive error 254 8d05h 1262d 0/26 upstream: reported C repro on 2020/12/13 21:13
linux-6.1 INFO: task hung in fuse_simple_request 6 192d 280d 0/3 auto-obsoleted due to no activity on 2024/02/26 14:29
upstream INFO: task can't die in request_wait_answer fuse C error 14 833d 1343d 0/26 auto-obsoleted due to no activity on 2023/04/16 22:02

Sample crash report:
INFO: task syz-executor.4:21782 blocked for more than 143 seconds.
      Not tainted 5.15.137-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:25400 pid:21782 ppid:  3538 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 request_wait_answer fs/fuse/dev.c:411 [inline]
 __fuse_request_send fs/fuse/dev.c:430 [inline]
 fuse_simple_request+0x112f/0x1a00 fs/fuse/dev.c:515
 fuse_flush+0x5d2/0x800 fs/fuse/file.c:517
 filp_close+0xad/0x150 fs/open.c:1319
 close_files fs/file.c:432 [inline]
 put_files_struct+0x1b2/0x350 fs/file.c:447
 do_exit+0x684/0x2480 kernel/exit.c:867
 do_group_exit+0x144/0x310 kernel/exit.c:994
 get_signal+0xc66/0x14e0 kernel/signal.c:2889
 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f38391f5ae9
RSP: 002b:00007f3837714178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f38393151f8 RCX: 00007f38391f5ae9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f38393151f8
RBP: 00007f38393151f0 R08: 00007f38377146c0 R09: 00007f38377146c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f38393151fc
R13: 000000000000006e R14: 00007fff2d22fc60 R15: 00007fff2d22fd48
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91f020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by udevd/2965:
2 locks held by getty/3259:
 #0: ffff888024ca8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bb32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by kworker/u4:8/3703:
2 locks held by kworker/1:14/22166:
1 lock held by syz-executor.4/23290:
4 locks held by syz-executor.1/23317:

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.137-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 23290 Comm: syz-executor.4 Not tainted 5.15.137-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
RIP: 0010:lock_release+0x156/0x9a0 kernel/locking/lockdep.c:5638
Code: 00 00 4c 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 5c 34 67 00 4c 89 6c 24 50 48 c7 84 24 b0 00 00 00 00 00 00 00 9c <8f> 84 24 b0 00 00 00 42 80 3c 3b 00 74 08 4c 89 f7 e8 b4 33 67 00
RSP: 0018:ffffc9000473f438 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 1ffff920008e7e9e RCX: ffffffff8162a348
RDX: 0000000000000000 RSI: ffffffff8ad87b20 RDI: ffffffff8ad87ae0
RBP: ffffc9000473f570 R08: dffffc0000000000 R09: fffffbfff1bc71e6
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920008e7e94
R13: ffffffff882f50b7 R14: ffffc9000473f4f0 R15: dffffc0000000000
FS:  00007fbfce3256c0(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020404030 CR3: 000000001a9fd000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline]
 _raw_spin_unlock_irqrestore+0x75/0x130 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline]
 __skb_try_recv_datagram+0x1c7/0x6a0 net/core/datagram.c:267
 __unix_dgram_recvmsg+0x3c1/0x1260 net/unix/af_unix.c:2316
 ____sys_recvmsg+0x286/0x530
 ___sys_recvmsg+0x1ec/0x690 net/socket.c:2690
 do_recvmmsg+0x36f/0x8f0 net/socket.c:2784
 __sys_recvmmsg net/socket.c:2863 [inline]
 __do_sys_recvmmsg net/socket.c:2886 [inline]
 __se_sys_recvmmsg net/socket.c:2879 [inline]
 __x64_sys_recvmmsg+0x195/0x240 net/socket.c:2879
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fbfcfde5ae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbfce3250c8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fbfcff05120 RCX: 00007fbfcfde5ae9
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000006
RBP: 00007fbfcfe3147a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fbfcff05120 R15: 00007ffed19a8ba8
 </TASK>

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/10/26 13:58 linux-5.15.y 12952a23a5da 23afc60f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2023/10/25 17:33 linux-5.15.y 12952a23a5da 72e794c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2023/10/24 04:35 linux-5.15.y 00c03985402e af8d2e46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2023/10/09 17:27 linux-5.15.y 1edcec18cfb7 3c53c7d9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2023/08/26 09:49 linux-5.15.y f6f7927ac664 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2023/08/24 10:12 linux-5.15.y f6f7927ac664 4d7ae7ab .config console log report info ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2023/08/22 19:23 linux-5.15.y f6f7927ac664 b81ca3f6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2023/08/08 23:42 linux-5.15.y c275eaaaa342 9552ae77 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2023/08/08 15:56 linux-5.15.y 38d4ca22a528 9552ae77 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2023/08/04 00:56 linux-5.15.y 38d4ca22a528 74621247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2023/07/26 16:41 linux-5.15.y 5c6a716301d9 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2023/07/20 11:09 linux-5.15.y d54cfc420586 4547cdf9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in fuse_simple_request
* Struck through repros no longer work on HEAD.