INFO: task hung in evict (2)

Status: upstream: reported C repro on 2024/02/14 14:00
Subsystems: squashfs
[Documentation on labels]
First crash: 125d, last: 52d
Cause bisection: introduced by (bisect log) :
commit e994f5b677ee016a2535d9df826315122da1ae65
Author: Vincent Whitchurch <>
Date: Wed May 17 14:18:19 2023 +0000

  squashfs: cache partial compressed blocks

Crash: INFO: task hung in evict (log)
Repro: C syz .config
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [squashfs?] INFO: task hung in evict (2) 0 (1) 2024/02/14 14:00
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in evict ext4 1 667d 667d 0/26 auto-closed as invalid on 2022/09/22 02:36
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/02/28 10:50 18m retest repro upstream report log

Sample crash report:
INFO: task syz-executor382:5067 blocked for more than 143 seconds.
      Not tainted 6.8.0-rc4-syzkaller-00005-gc664e16bb1ba #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor382 state:D stack:24216 pid:5067  tgid:5067  ppid:5064   flags:0x00004002
Call Trace:
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x17d1/0x49f0 kernel/sched/core.c:6727
 __schedule_loop kernel/sched/core.c:6802 [inline]
 schedule+0x149/0x260 kernel/sched/core.c:6817
 io_schedule+0x8c/0x110 kernel/sched/core.c:9023
 folio_wait_bit_common+0x881/0x12b0 mm/filemap.c:1274
 truncate_inode_pages_range+0xa8b/0xf70 mm/truncate.c:412
 evict+0x2bd/0x630 fs/inode.c:667
 dispose_list fs/inode.c:698 [inline]
 evict_inodes+0x5f8/0x690 fs/inode.c:748
 generic_shutdown_super+0x9d/0x2d0 fs/super.c:631
 kill_block_super+0x44/0x90 fs/super.c:1680
 deactivate_locked_super+0xc6/0x130 fs/super.c:477
 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267
 task_work_run+0x250/0x310 kernel/task_work.c:180
 ptrace_notify+0x2d1/0x380 kernel/signal.c:2390
 ptrace_report_syscall include/linux/ptrace.h:411 [inline]
 ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline]
 syscall_exit_work+0xbb/0x170 kernel/entry/common.c:167
 syscall_exit_to_user_mode_prepare kernel/entry/common.c:194 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:199 [inline]
 syscall_exit_to_user_mode+0x27f/0x370 kernel/entry/common.c:212
 do_syscall_64+0x108/0x240 arch/x86/entry/common.c:89
RIP: 0033:0x7f0f31f293c7
RSP: 002b:00007fff0cb79da8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f0f31f293c7
RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007fff0cb79e60
RBP: 00007fff0cb79e60 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007fff0cb7aed0
R13: 00005555560276c0 R14: 0000000000000007 R15: 431bde82d7b634db

Showing all locks held in the system:
1 lock held by khungtaskd/28:
 #0: ffffffff8e130ae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #0: ffffffff8e130ae0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #0: ffffffff8e130ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
2 locks held by getty/4820:
 #0: ffff88802fed20a0 (&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+0x6b4/0x1e10 drivers/tty/n_tty.c:2201
1 lock held by syz-executor382/5067:
 #0: ffff88801193e0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88801193e0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88801193e0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:509


NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.8.0-rc4-syzkaller-00005-gc664e16bb1ba #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
 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+0xfaf/0xff0 kernel/hung_task.c:379
 kthread+0x2f1/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 60 Comm: kworker/u4:4 Not tainted 6.8.0-rc4-syzkaller-00005-gc664e16bb1ba #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:smp_call_function_many_cond+0x2200/0x2960 kernel/smp.c:778
Code: 0f 85 03 02 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 01 db e9 09 e8 9c c6 0b 00 e9 47 e0 ff ff 65 8b 1d c8 e1 7a 7e <31> ff 89 de e8 c7 ca 0b 00 85 db 0f 84 12 01 00 00 e8 7a c6 0b 00
RSP: 0018:ffffc900015b7720 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff94482303
RDX: ffff8880187d0000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900015b7920 R08: ffffffff818797a2 R09: 1ffffffff1f0ab4d
R10: dffffc0000000000 R11: fffffbfff1f0ab4e R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff8f855a68 R15: 0000000000000003
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005612dea05600 CR3: 000000002bc1a000 CR4: 0000000000350ef0
Call Trace:
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2087 [inline]
 text_poke_bp_batch+0x726/0xb30 arch/x86/kernel/alternative.c:2359
 text_poke_flush arch/x86/kernel/alternative.c:2488 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2495
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_disable_cpuslocked+0xce/0x1c0 kernel/jump_label.c:235
 static_key_disable+0x1a/0x20 kernel/jump_label.c:243
 toggle_allocation_gate+0x1b8/0x250 mm/kfence/core.c:831
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x915/0x1420 kernel/workqueue.c:2706
 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787
 kthread+0x2f1/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.016 msecs

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/13 23:57 upstream c664e16bb1ba e66542d7 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kasan-gce-root INFO: task hung in evict
2023/12/18 07:14 upstream 0e389834672c 3222d10c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in evict
* Struck through repros no longer work on HEAD.