syzbot


INFO: task hung in fuse_lookup (3)

Status: upstream: reported C repro on 2019/08/14 09:48
Subsystems: fuse
[Documentation on labels]
Reported-by: syzbot+b64df836ad08c8e31a47@syzkaller.appspotmail.com
First crash: 1869d, last: 10h16m
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: INFO: task hung in lookup_slow (log)
Repro: C syz .config
  
Fix bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
INFO: task hung in fuse_lookup (3) 0 (1) 2019/08/14 09:48
Similar bugs (10)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: task hung in fuse_lookup 4 1656d 1809d 0/1 auto-closed as invalid on 2020/01/29 21:30
linux-4.19 INFO: task hung in fuse_lookup reiserfs C error 12 427d 1705d 0/1 upstream: reported C repro on 2019/08/14 05:24
linux-4.14 INFO: task hung in fuse_lookup (3) 1 820d 820d 0/1 auto-closed as invalid on 2022/05/15 00:47
linux-6.1 INFO: task hung in fuse_lookup origin:upstream syz 3 13d 312d 0/3 upstream: reported syz repro on 2023/06/07 05:32
linux-5.15 INFO: task hung in fuse_lookup origin:upstream syz error 2 292d 312d 0/3 upstream: reported syz repro on 2023/06/07 02:49
linux-4.14 INFO: task hung in fuse_lookup (4) reiserfs C 2 433d 488d 0/1 upstream: reported C repro on 2022/12/13 09:09
linux-4.14 INFO: task hung in fuse_lookup (2) 1 1490d 1490d 0/1 auto-closed as invalid on 2020/07/13 23:30
upstream INFO: task hung in fuse_lookup fuse 16 2049d 2101d 0/26 closed as invalid on 2018/09/05 12:51
android-49 INFO: task hung in fuse_lookup C 112 1618d 1830d 0/3 public: reported C repro on 2019/04/11 08:44
upstream INFO: task hung in fuse_lookup (2) fuse C 13 1883d 2043d 0/26 closed as dup on 2018/09/10 08:43
Last patch testing requests (10)
Created Duration User Patch Repo Result
2024/04/02 08:41 9h26m retest repro upstream error OK
2024/04/02 08:41 24m retest repro upstream error OK
2024/04/02 08:41 24m retest repro upstream error OK
2024/04/02 08:41 30m retest repro upstream error OK
2024/04/02 08:41 25m retest repro linux-next report log
2024/03/09 01:54 19m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2024/03/09 01:54 19m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2024/03/09 01:54 19m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2024/02/14 06:31 13m retest repro upstream report log
2024/01/31 04:44 15m retest repro upstream report log

Sample crash report:
INFO: task syz-executor.0:5086 blocked for more than 143 seconds.
      Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:19248 pid:5086  tgid:5086  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x17d3/0x4a20 kernel/sched/core.c:6736
 __schedule_loop kernel/sched/core.c:6813 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6828
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6885
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 fuse_lock_inode+0xd3/0x120 fs/fuse/inode.c:544
 fuse_lookup+0x115/0x600 fs/fuse/dir.c:424
 __lookup_slow+0x28e/0x3f0 fs/namei.c:1692
 lookup_slow+0x53/0x70 fs/namei.c:1709
 walk_component fs/namei.c:2004 [inline]
 link_path_walk+0x9ea/0xea0 fs/namei.c:2331
 path_openat+0x24a/0x3240 fs/namei.c:3795
 do_filp_open+0x235/0x490 fs/namei.c:3826
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_openat fs/open.c:1437 [inline]
 __se_sys_openat fs/open.c:1432 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1432
 do_syscall_64+0xfd/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f07d0c7d801
RSP: 002b:00007ffd51254b00 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f07d0c7d801
RDX: 0000000000090800 RSI: 00007f07d0cc945d RDI: 00000000ffffff9c
RBP: 00007ffd51254bcc R08: 0000000000000000 R09: 00007f07d19390b0
R10: 0000000000000000 R11: 0000000000000287 R12: 0000000000000000
R13: 00000000000152b5 R14: 00000000000151d2 R15: 0000000000000006
 </TASK>
INFO: task syz-executor.0:5105 blocked for more than 143 seconds.
      Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:23896 pid:5105  tgid:5103  ppid:5086   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x17d3/0x4a20 kernel/sched/core.c:6736
 __schedule_loop kernel/sched/core.c:6813 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6828
 request_wait_answer fs/fuse/dev.c:407 [inline]
 __fuse_request_send fs/fuse/dev.c:426 [inline]
 fuse_simple_request+0x1199/0x1b90 fs/fuse/dev.c:513
 fuse_lookup_name+0x332/0x830 fs/fuse/dir.c:386
 fuse_lookup+0x182/0x600 fs/fuse/dir.c:425
 __lookup_slow+0x28e/0x3f0 fs/namei.c:1692
 lookup_slow+0x53/0x70 fs/namei.c:1709
 walk_component fs/namei.c:2004 [inline]
 link_path_walk+0x9ea/0xea0 fs/namei.c:2331
 path_openat+0x24a/0x3240 fs/namei.c:3795
 do_filp_open+0x235/0x490 fs/namei.c:3826
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_openat fs/open.c:1437 [inline]
 __se_sys_openat fs/open.c:1432 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1432
 do_syscall_64+0xfd/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f07d0c7c9a0
RSP: 002b:00007f07d1916e30 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f07d0c7c9a0
RDX: 0000000000000002 RSI: 00007f07d1916f40 RDI: 00000000ffffff9c
RBP: 00007f07d1916f40 R08: 0000000000000000 R09: 0000000000000427
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
R13: 00007f07d1916f80 R14: 00007f07d1916f40 R15: 00007f07c7a00000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
2 locks held by getty/4825:
 #0: ffff88802a1e50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
2 locks held by syz-executor.0/5086:
 #0: ffff8880786a8150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:803 [inline]
 #0: ffff8880786a8150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1708
 #1: ffff8880786a85c8 (&fi->mutex){+.+.}-{3:3}, at: fuse_lock_inode+0xd3/0x120 fs/fuse/inode.c:544
2 locks held by syz-executor.0/5105:
 #0: ffff8880786a8150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:803 [inline]
 #0: ffff8880786a8150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1708
 #1: ffff8880786a85c8 (&fi->mutex){+.+.}-{3:3}, at: fuse_lock_inode+0xd3/0x120 fs/fuse/inode.c:544

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xfb0/0xff0 kernel/hung_task.c:379
 kthread+0x2f2/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4506 Comm: syslogd Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
RIP: 0010:check_preemption_disabled+0x2/0x120 lib/smp_processor_id.c:13
Code: d2 fe 8b 48 c7 c6 e0 d2 fe 8b eb 1c 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 <41> 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24
RSP: 0018:ffffc9000314fb68 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000001
RDX: ffff88807e7a5a00 RSI: ffffffff8baad360 RDI: ffffffff8bfed300
RBP: ffffc9000314fc48 R08: ffffffff82096910 R09: 1ffffffff1f0e74d
R10: dffffc0000000000 R11: fffffbfff1f0e74e R12: 0000000000000246
R13: ffff88807e7a5a00 R14: 00000000ffffffff R15: ffffffff8e132020
FS:  00007ff545500380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056355dc4d600 CR3: 000000002b200000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline]
 lock_is_held_type+0x101/0x190 kernel/locking/lockdep.c:5826
 lock_is_held include/linux/lockdep.h:231 [inline]
 rcu_read_lock_any_held+0x8d/0x160 kernel/rcu/update.c:386
 rcu_sync_is_idle include/linux/rcu_sync.h:34 [inline]
 percpu_up_read include/linux/percpu-rwsem.h:105 [inline]
 __sb_end_write include/linux/fs.h:1657 [inline]
 sb_end_write+0x49/0x1c0 include/linux/fs.h:1750
 file_end_write include/linux/fs.h:2873 [inline]
 vfs_write+0x786/0xcb0 fs/read_write.c:598
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_64+0xfd/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7ff545654bf2
Code: 89 c7 48 89 44 24 08 e8 7b 34 fa ff 48 8b 44 24 08 48 83 c4 28 c3 c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 6f 48 8b 15 07 a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffc4bc83838 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007ff545654bf2
RDX: 000000000000005b RSI: 000056331e9dbc50 RDI: 0000000000000003
RBP: 000056331e9dbc50 R08: 0000000000000001 R09: 0000000000000000
R10: 00007ff5457f33a3 R11: 0000000000000246 R12: 000000000000005b
R13: 00007ff545500300 R14: 0000000000000004 R15: 000056331e9dba60
 </TASK>

Crashes (45):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/16 04:27 upstream fe46a7dd189e d615901c .config strace log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kasan-gce-root INFO: task hung in fuse_lookup
2023/10/29 17:29 upstream 2af9b20dbb39 3c418d72 .config strace log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kasan-gce-smack-root INFO: task hung in fuse_lookup
2023/06/23 16:29 upstream 8a28a0b6f1a1 09ffe269 .config strace log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kasan-gce-smack-root INFO: task hung in fuse_lookup
2023/02/22 08:55 upstream 4a7d37e824f5 42a4d508 .config strace log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kasan-gce-root INFO: task hung in fuse_lookup
2023/01/01 03:28 upstream c8451c141e07 ab32d508 .config strace log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs INFO: task hung in fuse_lookup
2024/01/17 04:44 upstream 052d534373b7 2a7bcc7f .config console log report syz [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-qemu2-arm32 INFO: task hung in fuse_lookup
2024/01/14 18:45 upstream 052d534373b7 551587c1 .config console log report syz [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-qemu2-arm64 INFO: task hung in fuse_lookup
2023/08/13 09:53 linux-next 21ef7b1e17d0 39990d51 .config strace log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-linux-next-kasan-gce-root INFO: task hung in fuse_lookup
2023/03/19 19:40 linux-next 6f08c1de13a9 7939252e .config strace log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-linux-next-kasan-gce-root INFO: task hung in fuse_lookup
2023/12/01 15:46 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2cc14f52aeb7 f819d6f7 .config console log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 INFO: task hung in fuse_lookup
2023/06/07 08:07 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci cd6bd67ad7ab a4ae4f42 .config console log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 INFO: task hung in fuse_lookup
2022/12/29 19:46 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a5541c0811a0 44712fbc .config console log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 INFO: task hung in fuse_lookup
2019/08/14 05:38 upstream ee1c7bd33e66 ef801a3e .config console log report syz C ci-upstream-kasan-gce-root
2019/08/14 04:14 upstream ee1c7bd33e66 ef801a3e .config console log report syz C ci-upstream-kasan-gce-smack-root
2019/08/14 02:35 upstream ee1c7bd33e66 ef801a3e .config console log report syz C ci-upstream-kasan-gce-selinux-root
2024/04/14 08:32 upstream fe46a7dd189e c8349e48 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in fuse_lookup
2024/02/23 20:48 upstream ffd2cb6b718e 8d446f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in fuse_lookup
2023/12/25 12:55 upstream 861deac3b092 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in fuse_lookup
2023/12/22 16:50 upstream 24e0d2e527a3 4f9530a3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in fuse_lookup
2023/11/02 03:02 upstream 8bc9e6515183 69904c9f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in fuse_lookup
2023/07/11 12:23 upstream 3f01e9fed845 f8780940 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in fuse_lookup
2023/06/30 08:42 upstream 6f612579be9d 7b33cf8f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in fuse_lookup
2023/04/18 13:34 upstream 6a8f57ae2eb0 436577a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in fuse_lookup
2022/12/12 14:20 upstream 4cee37b3a4e6 67be1ae7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in fuse_lookup
2022/10/31 01:24 upstream b229b6ca5abb 2a71366b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in fuse_lookup
2022/09/18 15:20 upstream a335366bad13 dd9a85ff .config console log report info ci-upstream-kasan-gce-selinux-root INFO: task hung in fuse_lookup
2022/08/15 08:52 upstream 7ebfc85e2cd7 8dfcaa3d .config console log report info ci-upstream-kasan-gce-smack-root INFO: task hung in fuse_lookup
2022/08/12 04:40 upstream 7ebfc85e2cd7 402cd70d .config console log report info ci-upstream-kasan-gce-root INFO: task hung in fuse_lookup
2022/01/27 09:31 upstream 0280e3c58f92 2cbffd88 .config console log report info ci-upstream-kasan-gce-root INFO: task hung in fuse_lookup
2021/10/02 17:54 upstream 53d5fc89d66a db0f5787 .config console log report info ci-upstream-kasan-gce-selinux-root INFO: task hung in fuse_lookup
2023/12/01 11:30 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2cc14f52aeb7 f819d6f7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in fuse_lookup
2022/01/13 12:21 linux-next 27c9d5b3c24a 44d1319a .config console log report info ci-upstream-linux-next-kasan-gce-root INFO: task hung in fuse_lookup
2021/01/14 21:40 upstream 65f0d2414b70 65a7a854 .config console log report info ci-upstream-kasan-gce-selinux-root
2021/01/14 21:29 upstream 65f0d2414b70 65a7a854 .config console log report info ci-upstream-kasan-gce-root
2021/01/14 21:28 upstream 65f0d2414b70 65a7a854 .config console log report info ci-upstream-kasan-gce
2020/02/23 06:34 upstream 54dedb5b571d 2c36e7a7 .config console log report ci-upstream-kasan-gce-selinux-root
2019/04/05 20:58 upstream ea2cec24c8d4 40f2363e .config console log report ci-upstream-kasan-gce-selinux-root
2019/03/25 12:04 upstream 8c2ffd917477 2c86e0a5 .config console log report ci-upstream-kasan-gce-root
2019/03/22 15:25 upstream 0939221e6468 dce6e62f .config console log report ci-upstream-kasan-gce-root
2019/03/20 03:42 upstream b7a42146dca3 2458c1c6 .config console log report ci-upstream-kasan-gce-selinux-root
2019/03/19 17:14 upstream 9e98c678c2d6 e4549234 .config console log report ci-upstream-kasan-gce-selinux-root
2019/03/18 18:47 upstream 9e98c678c2d6 4656beca .config console log report ci-upstream-kasan-gce-root
2019/03/02 20:03 upstream c93d9218ea56 1c0e457a .config console log report ci-upstream-kasan-gce-selinux-root
2019/12/23 21:57 linux-next 7ddd09fc4b74 be5c2c81 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/03/17 04:58 linux-next cf08baa29613 bab43553 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.