INFO: task syz.2.261:9037 blocked for more than 143 seconds.
Not tainted 6.15.0-rc7-syzkaller-00175-g0f8c0258bf04 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.261 state:D stack:25144 pid:9037 tgid:9034 ppid:7014 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
io_schedule+0x81/0xe0 kernel/sched/core.c:7742
bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:247
__wait_on_bit_lock+0xec/0x4f0 kernel/sched/wait_bit.c:90
out_of_line_wait_on_bit_lock+0x123/0x170 kernel/sched/wait_bit.c:117
lock_buffer include/linux/buffer_head.h:434 [inline]
hfs_mdb_commit+0xc8e/0x1160 fs/hfs/mdb.c:325
hfs_sync_fs+0x15/0x20 fs/hfs/super.c:37
sync_filesystem+0xee/0x230 fs/sync.c:56
hfs_reconfigure+0x66/0x270 fs/hfs/super.c:119
reconfigure_super+0x224/0x890 fs/super.c:1083
do_remount fs/namespace.c:3365 [inline]
path_mount+0xd18/0xfe0 fs/namespace.c:4200
do_mount fs/namespace.c:4221 [inline]
__do_sys_mount fs/namespace.c:4432 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4409
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f170559010a
RSP: 002b:00007f1706370e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f1706370ef0 RCX: 00007f170559010a
RDX: 0000200000000f40 RSI: 0000200000000f00 RDI: 0000000000000000
RBP: 0000200000000f40 R08: 00007f1706370ef0 R09: 0000000001258438
R10: 0000000001258438 R11: 0000000000000246 R12: 0000200000000f00
R13: 00007f1706370eb0 R14: 0000000000000000 R15: 0000200000000f80
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
#0: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#0: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998
1 lock held by khungtaskd/31:
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
3 locks held by kworker/u8:5/140:
3 locks held by kworker/u8:7/4467:
2 locks held by getty/5581:
#0:
ffff8880307520a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900033332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by udevd/5817:
2 locks held by kworker/0:6/5914:
#0: ffff88801a081548 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a081548 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc9000b1c7c60 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000b1c7c60 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
1 lock held by udevd/6566:
1 lock held by syz.2.261/9037:
#0: ffff88804ac820e0 (&type->s_umount_key#104){+.+.}-{4:4}, at: do_remount fs/namespace.c:3362 [inline]
#0: ffff88804ac820e0 (&type->s_umount_key#104){+.+.}-{4:4}, at: path_mount+0xcd2/0xfe0 fs/namespace.c:4200
2 locks held by syz-executor/10708:
#0: ffff88807ecee0e0 (&type->s_umount_key#69){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88807ecee0e0 (&type->s_umount_key#69){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88807ecee0e0 (&type->s_umount_key#69){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
#1: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#1: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
2 locks held by syz.1.479/11460:
#0: ffff8880492640e0 (&type->s_umount_key#64/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:344
#1: ffffffff8dde54a8 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5179 [inline]
#1: ffffffff8dde54a8 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0x9eb/0x1b70 kernel/workqueue.c:5734
2 locks held by syz.7.482/11463:
2 locks held by syz.9.480/11468:
3 locks held by dhcpcd-run-hook/11495:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-syzkaller-00175-g0f8c0258bf04 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11468 Comm: syz.9.480 Not tainted 6.15.0-rc7-syzkaller-00175-g0f8c0258bf04 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:check_preemption_disabled+0x40/0x120 lib/smp_processor_id.c:55
Code: 08 65 8b 05 56 ee 22 07 65 8b 0d 4b ee 22 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d 2b ee 22 07 48 3b 4c 24 08 0f 85 cc 00 00 00 <48> 83 c4 10 5b 41 5e 41 5f 5d e9 51 b5 02 00 cc 48 c7 04 24 00 00
RSP: 0018:ffffc90004cef6a0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff849bb09d RCX: 4b96657eef4ef300
RDX: ffff88802eb3bc00 RSI: ffffffff8bc122e0 RDI: ffffffff8bc122a0
RBP: 0000000000000000 R08: ffffffff999a36e7 R09: 1ffffffff33346dc
R10: dffffc0000000000 R11: fffffbfff33346dd R12: dffffc0000000000
R13: 0000000000000cc0 R14: 0000000000000001 R15: ffffffff999a36e4
FS: 00007f7a6b6216c0(0000) GS:ffff8881260f6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f961e5f2b60 CR3: 0000000045548000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:736
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
blk_cgroup_congested+0x17d/0x210 block/blk-cgroup.c:2263
__folio_throttle_swaprate+0x80/0x1c0 mm/swapfile.c:3923
folio_throttle_swaprate include/linux/swap.h:634 [inline]
shmem_add_to_page_cache+0x72c/0xb10 mm/shmem.c:898
shmem_alloc_and_add_folio+0x846/0xf60 mm/shmem.c:1919
shmem_get_folio_gfp+0x597/0x15f0 mm/shmem.c:2533
shmem_get_folio mm/shmem.c:2639 [inline]
shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3289
generic_perform_write+0x2c4/0x910 mm/filemap.c:4103
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3464
new_sync_write fs/read_write.c:591 [inline]
vfs_write+0x54b/0xa90 fs/read_write.c:684
ksys_write+0x145/0x250 fs/read_write.c:736
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7a6a78d41f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007f7a6b620df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f7a6a78d41f
RDX: 0000000001000000 RSI: 00007f7a60000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000050ed
R10: 000020000000a2c2 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f7a6b620ef0 R14: 00007f7a6b620eb0 R15: 00007f7a60000000