syzbot


INFO: task hung in block_invalidate_folio

Status: upstream: reported on 2026/03/16 23:48
Reported-by: syzbot+ae6451f2388fdaa56124@syzkaller.appspotmail.com
First crash: 24d, last: 11d
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in block_invalidate_folio (2) 1 4 9d07h 55d 0/3 upstream: reported on 2026/02/14 00:20
upstream INFO: task hung in block_invalidate_folio (2) gfs2 1 C error 154 5h36m 242d 0/29 upstream: reported C repro on 2025/08/11 03:13
upstream INFO: task hung in block_invalidate_folio gfs2 1 2 459d 471d 0/29 auto-obsoleted due to no activity on 2025/03/07 11:30
linux-6.1 INFO: task hung in block_invalidate_folio 1 syz error 1 329d 329d 0/3 auto-obsoleted due to no activity on 2025/08/24 15:41

Sample crash report:
INFO: task kworker/0:1H:97 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1H    state:D stack:26392 pid:97    ppid:2      flags:0x00004000
Workqueue: glock_workqueue glock_work_func

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 io_schedule+0x80/0xd0 kernel/sched/core.c:9023
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xdc/0x580 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x13c/0x190 kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer fs/buffer.c:71 [inline]
 lock_buffer include/linux/buffer_head.h:385 [inline]
 discard_buffer fs/buffer.c:1564 [inline]
 block_invalidate_folio+0x389/0x9b0 fs/buffer.c:1621
 folio_invalidate mm/truncate.c:158 [inline]
 truncate_cleanup_folio+0x220/0x5c0 mm/truncate.c:178
 truncate_inode_pages_range+0x28a/0xfb0 mm/truncate.c:392
 do_xmote+0x779/0x12b0 fs/gfs2/glock.c:764
 glock_work_func+0x29e/0x4c0 fs/gfs2/glock.c:1119
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task syz-executor:5932 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21640 pid:5932  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0xc1/0x2d0 kernel/time/timer.c:2144
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion+0x2cb/0x5b0 kernel/sched/completion.c:148
 __flush_work+0x913/0xaa0 kernel/workqueue.c:3471
 flush_work kernel/workqueue.c:3492 [inline]
 flush_delayed_work+0x131/0x180 kernel/workqueue.c:3616
 gfs2_clear_rgrpd+0xd7/0x680 fs/gfs2/rgrp.c:731
 gfs2_put_super+0x8ab/0x930 fs/gfs2/super.c:647
 generic_shutdown_super+0x134/0x2b0 fs/super.c:693
 kill_block_super+0x44/0x90 fs/super.c:1660
 deactivate_locked_super+0x97/0x100 fs/super.c:481
 cleanup_mnt+0x43b/0x4d0 fs/namespace.c:1259
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9a6319da57
RSP: 002b:00007ffd0aa4abf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f9a63232048 RCX: 00007f9a6319da57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd0aa4acb0
RBP: 00007ffd0aa4acb0 R08: 00007ffd0aa4bcb0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd0aa4bd40
R13: 00007f9a63232048 R14: 000000000002fc06 R15: 00007ffd0aa4bd80
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
4 locks held by kworker/u4:3/49:
 #0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
 #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
 #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2176/0x45a0 kernel/sched/core.c:6695
 #2: ffff8880b8e29598 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x73b/0xdb0 kernel/time/timer.c:1112
 #3: ffffffff974ab960 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x6c/0x4f0 lib/debugobjects.c:709
2 locks held by kworker/0:1H/97:
 #0: ffff88801eaec938 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff88801eaec938 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc900024cfd00 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc900024cfd00 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
4 locks held by kworker/u4:9/2943:
 #0: ffff8880182f0938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff8880182f0938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc9000b9e7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc9000b9e7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffff888024856388 (&wb->work_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline]
 #2: ffff888024856388 (&wb->work_lock){..-.}-{2:2}, at: wb_wakeup_delayed+0x59/0x100 mm/backing-dev.c:394
 #3: ffff8880b8e29598 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x73b/0xdb0 kernel/time/timer.c:1112
2 locks held by getty/5527:
 #0: ffff88802d6950a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
1 lock held by syz-executor/5932:
 #0: ffff88807cee40e0 (&type->s_umount_key#89){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88807cee40e0 (&type->s_umount_key#89){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88807cee40e0 (&type->s_umount_key#89){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 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+0xf3d/0xf80 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 12 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4789 [inline]
RIP: 0010:__lock_acquire+0x747/0x7d40 kernel/locking/lockdep.c:5087
Code: 83 f8 31 73 43 48 8d 04 9b 49 8d 5c c5 00 48 89 d8 48 c1 e8 03 42 0f b6 04 00 84 c0 75 45 8b 1b 48 8b 44 24 48 42 0f b6 04 00 <84> c0 75 55 48 8b 44 24 10 33 18 41 ff ce 49 ff cf f7 c3 00 60 00
RSP: 0018:ffffc90000117700 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 00000000000406d2 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911c35d8
RBP: ffffc90000117948 R08: dffffc0000000000 R09: 1ffffffff22386bb
R10: dffffc0000000000 R11: fffffbfff22386bc R12: 0000000000000000
R13: ffff88801b27e500 R14: 0000000000000003 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9c083e92f8 CR3: 000000007a3b5000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 batadv_nc_purge_paths+0xe7/0x3a0 net/batman-adv/network-coding.c:442
 batadv_nc_worker+0x369/0x610 net/batman-adv/network-coding.c:722
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/30 01:55 linux-6.6.y c09fbcd31ae6 b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in block_invalidate_folio
2026/03/16 23:47 linux-6.6.y 4fc00fe35d46 0737c18f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in block_invalidate_folio
* Struck through repros no longer work on HEAD.