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INFO: task hung in fuse_flush (5)

Status: auto-obsoleted due to no activity on 2025/06/08 10:49
Subsystems: fuse
[Documentation on labels]
First crash: 104d, last: 99d
Similar bugs (11)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in fuse_flush 1 1551d 1551d 0/1 auto-closed as invalid on 2021/07/16 16:14
linux-6.1 INFO: task hung in fuse_flush 1 109d 109d 0/3 auto-obsoleted due to no activity on 2025/06/08 05:58
upstream INFO: task hung in fuse_flush (2) fuse 2 875d 884d 0/28 auto-obsoleted due to no activity on 2023/04/24 00:25
upstream INFO: task hung in fuse_flush (4) fuse 6 212d 358d 0/28 auto-obsoleted due to no activity on 2025/02/15 08:56
upstream INFO: task hung in fuse_flush fuse 2 1320d 1408d 0/28 auto-closed as invalid on 2022/02/03 03:15
linux-6.1 INFO: task hung in fuse_flush (2) 1 8d03h 8d03h 0/3 upstream: reported on 2025/06/09 09:24
linux-5.15 INFO: task hung in fuse_flush 1 359d 359d 0/3 auto-obsoleted due to no activity on 2024/09/30 23:08
linux-4.19 INFO: task hung in fuse_flush (2) 1 1360d 1360d 0/1 auto-closed as invalid on 2022/01/24 04:40
linux-4.14 INFO: task hung in fuse_flush C inconclusive 19 916d 1237d 0/1 upstream: reported C repro on 2022/01/26 21:17
linux-4.19 INFO: task hung in fuse_flush (3) 109 875d 1237d 0/1 upstream: reported on 2022/01/27 11:57
upstream INFO: task hung in fuse_flush (3) fuse 1 628d 628d 0/28 auto-obsoleted due to no activity on 2023/12/26 21:09

Sample crash report:
INFO: task syz.8.5816:29830 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.5816      state:D stack:24160 pid:29830 tgid:29830 ppid:27819  task_flags:0x400040 flags:0x00000006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x190e/0x4c90 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1d7/0x220 kernel/locking/rwsem.c:1578
 inode_lock include/linux/fs.h:877 [inline]
 fuse_flush+0x291/0x990 fs/fuse/file.c:535
 filp_flush+0xb9/0x190 fs/open.c:1540
 filp_close+0x1e/0x40 fs/open.c:1553
 __range_close fs/file.c:746 [inline]
 __do_sys_close_range fs/file.c:805 [inline]
 __se_sys_close_range+0x38b/0x6d0 fs/file.c:769
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faeff38d169
RSP: 002b:00007ffdac3ebc68 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007faeff5a7ba0 RCX: 00007faeff38d169
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007faeff5a7ba0 R08: 000000000000b9bc R09: 0000000aac3ebf5f
R10: 00007faeff5a7ac0 R11: 0000000000000246 R12: 00000000001e3966
R13: 00007ffdac3ebd60 R14: ffffffffffffffff R15: 00007ffdac3ebd80
 </TASK>
INFO: task syz.8.5816:29838 blocked for more than 145 seconds.
      Not tainted 6.14.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.5816      state:D stack:24952 pid:29838 tgid:29830 ppid:27819  task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x190e/0x4c90 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 fuse_set_nowrite+0x216/0x350 fs/fuse/dir.c:1829
 fuse_sync_writes fs/fuse/file.c:512 [inline]
 fuse_fsync+0x15b/0x310 fs/fuse/file.c:614
 generic_write_sync include/linux/fs.h:2970 [inline]
 generic_file_write_iter+0x2fa/0x5e0 mm/filemap.c:4319
 fuse_cache_write_iter fs/fuse/file.c:1466 [inline]
 fuse_file_write_iter+0x9b9/0xfd0 fs/fuse/file.c:1807
 do_iter_readv_writev+0x71c/0x9d0
 vfs_writev+0x38b/0xbc0 fs/read_write.c:1050
 do_writev+0x1b6/0x360 fs/read_write.c:1096
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faeff38d169
RSP: 002b:00007faf00130038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007faeff5a6160 RCX: 00007faeff38d169
RDX: 0000000000000001 RSI: 0000400000000000 RDI: 0000000000000004
RBP: 00007faeff40e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007faeff5a6160 R15: 00007ffdac3ebb08
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8eb39360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8eb39360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8eb39360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
1 lock held by udevd/5202:
2 locks held by getty/5591:
 #0: ffff888031a9b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
2 locks held by kworker/u8:11/8710:
1 lock held by syz.8.5816/29830:
 #0: ffff88807af75f88 (&sb->s_type->i_mutex_key#33){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
 #0: ffff88807af75f88 (&sb->s_type->i_mutex_key#33){+.+.}-{4:4}, at: fuse_flush+0x291/0x990 fs/fuse/file.c:535
3 locks held by syz.8.5816/29838:
 #0: ffff88806421ed38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x254/0x320 fs/file.c:1192
 #1: ffff88807b854420 (sb_writers#15){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3035 [inline]
 #1: ffff88807b854420 (sb_writers#15){.+.+}-{0:0}, at: vfs_writev+0x2d6/0xbc0 fs/read_write.c:1048
 #2: ffff88807af75f88 (&sb->s_type->i_mutex_key#33){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
 #2: ffff88807af75f88 (&sb->s_type->i_mutex_key#33){+.+.}-{4:4}, at: fuse_fsync+0x118/0x310 fs/fuse/file.c:603
1 lock held by syz.6.6111/31356:
1 lock held by rm/31476:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 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:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:399
 kthread+0x7ab/0x920 kernel/kthread.c:464
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 27387 Comm: kworker/u8:17 Not tainted 6.14.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:memcpy+0xe/0x20 arch/x86/lib/memcpy_64.S:39
Code: 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 48 89 f8 48 89 d1 f3 a4 <e9> 18 4e 07 f5 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90
RSP: 0018:ffffc9000f5df678 EFLAGS: 00000002
RAX: 00002aaaaaaab0e9 RBX: 00002aaaaaaab0e9 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff9343fcff RDI: 00002aaaaaaab0ed
RBP: ffffc9000f5df870 R08: 00002aaaaaaab0ed R09: 1ffffffff2687f9f
R10: dffffc0000000000 R11: fffffbfff2687fa0 R12: ffff88801b06f558
R13: ffffc9000f5df760 R14: 0000000000000004 R15: ffffffff9343fcfb
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000400000900000 CR3: 000000001b06a000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 text_poke_memcpy+0x25/0x30 arch/x86/kernel/alternative.c:1879
 __text_poke+0x788/0xd80 arch/x86/kernel/alternative.c:1956
 text_poke arch/x86/kernel/alternative.c:2017 [inline]
 text_poke_bp_batch+0x59c/0xb30 arch/x86/kernel/alternative.c:2350
 text_poke_flush arch/x86/kernel/alternative.c:2519 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2526
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_disable_cpuslocked+0xd2/0x1c0 kernel/jump_label.c:240
 static_key_disable+0x1a/0x20 kernel/jump_label.c:248
 toggle_allocation_gate+0x1bf/0x260 mm/kfence/core.c:855
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7ab/0x920 kernel/kthread.c:464
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/10 10:42 upstream 80e54e84911a 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in fuse_flush
2025/03/05 10:57 upstream 48a5eed9ad58 60f5d8d9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in fuse_flush
2025/03/10 08:51 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 77c95b8c7a16 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in fuse_flush
* Struck through repros no longer work on HEAD.