syzbot

INFO: task kworker/0:20:4448 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:20    state:D stack:24112 pid: 4448 ppid:     2 flags:0x00004000
Workqueue: gfs_recovery gfs2_recover_func

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
 wait_on_page_bit_common+0x83b/0xe50 mm/filemap.c:1356
 wait_on_page_locked include/linux/pagemap.h:688 [inline]
 gfs2_jhead_process_page+0x252/0xbf0 fs/gfs2/lops.c:476
 gfs2_find_jhead+0xec2/0x1000 fs/gfs2/lops.c:597
 gfs2_recover_func+0x73a/0x1cf0 fs/gfs2/recovery.c:462
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
INFO: task syz.0.17:4492 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:24208 pid: 4492 ppid:  4388 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 bit_wait+0xd/0xc0 kernel/sched/wait_bit.c:199
 __wait_on_bit kernel/sched/wait_bit.c:49 [inline]
 out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64
 wait_on_bit include/linux/wait_bit.h:76 [inline]
 gfs2_recover_journal+0x104/0x150 fs/gfs2/recovery.c:579
 init_journal+0x1779/0x22f0 fs/gfs2/ops_fstype.c:837
 init_inodes+0xdb/0x320 fs/gfs2/ops_fstype.c:891
 gfs2_fill_super+0x16b2/0x1f00 fs/gfs2/ops_fstype.c:1249
 get_tree_bdev+0x3f1/0x610 fs/super.c:1325
 gfs2_get_tree+0x4d/0x1e0 fs/gfs2/ops_fstype.c:1332
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fb071fda0ca
RSP: 002b:00007fff7221f3e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff7221f470 RCX: 00007fb071fda0ca
RDX: 0000200000037f40 RSI: 0000200000037f80 RDI: 00007fff7221f430
RBP: 0000200000037f40 R08: 00007fff7221f470 R09: 0000000000004000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000200000037f80
R13: 00007fff7221f430 R14: 0000000000037f56 R15: 0000200000037fc0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31f320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/1:2/2856:
2 locks held by getty/3944:
 #0: ffff88802ca3a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
2 locks held by kworker/0:20/4448:
 #0: ffff88801b991938 ((wq_completion)gfs_recovery){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc900030afd00 ((work_completion)(&jd->jd_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
1 lock held by syz.0.17/4492:
 #0: ffff88807304a0e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
3 locks held by syz.1.206/4782:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4567 Comm: udevd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_preemption_disabled+0x1f/0x110 lib/smp_processor_id.c:16
Code: 7a 8a 48 c7 c6 e0 06 7a 8a eb 00 55 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 05 79 2b 45 76 <65> 8b 0d e2 85 45 76 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00
RSP: 0018:ffffc90002f4f5d0 EFLAGS: 00000082
RAX: 0000000000000001 RBX: 0000607f46c54710 RCX: ffff88802a1b9dc0
RDX: 0000000000000000 RSI: ffffffff8a35f940 RDI: ffffffff8a7a0700
RBP: 0000000000000017 R08: ffffea0001616307 R09: 1ffffd40002c2c60
R10: dffffc0000000000 R11: fffff940002c2c61 R12: 0000000000000017
R13: ffffffffffffffff R14: ffff888075724000 R15: ffff8880255fc0c8
FS:  00007f8f5792a880(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f56fdd000 CR3: 000000007b1ec000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 memcg_rstat_updated mm/memcontrol.c:663 [inline]
 __mod_memcg_lruvec_state+0x109/0x190 mm/memcontrol.c:746
 __mod_lruvec_state mm/memcontrol.c:767 [inline]
 __mod_lruvec_page_state+0x1b6/0x330 mm/memcontrol.c:788
 unaccount_page_cache_page+0x449/0x870 mm/filemap.c:198
 __delete_from_page_cache+0xbe/0x6d0 mm/filemap.c:231
 delete_from_page_cache+0x121/0x190 mm/filemap.c:266
 truncate_inode_page+0x8d/0xb0 mm/truncate.c:219
 shmem_undo_range+0x53c/0x1930 mm/shmem.c:960
 shmem_truncate_range mm/shmem.c:1063 [inline]
 shmem_evict_inode+0x220/0xa40 mm/shmem.c:1145
 evict+0x4c9/0x8d0 fs/inode.c:647
 __dentry_kill+0x431/0x650 fs/dcache.c:586
 dentry_kill+0xb8/0x290 fs/dcache.c:-1
 dput+0xd8/0x1a0 fs/dcache.c:893
 __fput+0x5ee/0x930 fs/file_table.c:319
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8f57a18407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffd63a87160 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007f8f5792a880 RCX: 00007f8f57a18407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f8f5792a6e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 000055bd3702d410 R14: 0000000000000008 R15: 000055bd3703b820
 </TASK>