INFO: task syz-executor.0:4512 blocked for more than 143 seconds.
Not tainted 5.15.189-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:20160 pid: 4512 ppid: 1 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191
sync_inodes_sb+0x1b3/0x920 fs/fs-writeback.c:2770
sync_filesystem+0x16d/0x220 fs/sync.c:64
generic_shutdown_super+0x6b/0x300 fs/super.c:448
kill_block_super+0x7c/0xe0 fs/super.c:1427
deactivate_locked_super+0x93/0xf0 fs/super.c:335
cleanup_mnt+0x418/0x4d0 fs/namespace.c:1139
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+0xb1/0x140 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: 0033:0x7f7ec729be57
RSP: 002b:00007ffede029b68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f7ec72e53b9 RCX: 00007f7ec729be57
RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007ffede029c20
RBP: 00007ffede029c20 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffede02ace0
R13: 00007f7ec72e53b9 R14: 0000000000014c59 R15: 0000000000000008
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c11c360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:1/144:
#0: ffff8880191e0938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc900010afd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by getty/3961:
#0: ffff88802bbee098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
2 locks held by syz-executor.0/4512:
#0: ffff88807e03c0e0 (&type->s_umount_key#32){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
#1: ffff888020ad87d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
#1: ffff888020ad87d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2768
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:cpu_of kernel/sched/sched.h:1135 [inline]
RIP: 0010:list_add_leaf_cfs_rq kernel/sched/fair.c:292 [inline]
RIP: 0010:enqueue_entity+0xa4f/0x1e50 kernel/sched/fair.c:4511
Code: 7b 67 00 48 b9 00 00 00 00 00 fc ff df 4c 8b 3b 4d 8d b7 18 0b 00 00 4c 89 f0 48 c1 e8 03 0f b6 04 08 84 c0 0f 85 f8 05 00 00 <4d> 63 36 4d 8d a5 78 01 00 00 4c 89 e3 48 c1 eb 03 0f b6 04 0b 84
RSP: 0018:ffffc90000007d58 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880b903a530 RCX: dffffc0000000000
RDX: 0000000000000018 RSI: ffff8880b903a400 RDI: ffff88801d7a80d0
RBP: ffff8880b903a3d0 R08: dffffc0000000000 R09: ffff88801d7a80d0
R10: ffffed1003af501d R11: 1ffff11003af501a R12: ffff88801d7a80d0
R13: ffff8880b903a3c0 R14: ffff8880b903ae18 R15: ffff8880b903a300
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555e534dd168 CR3: 000000002ab9b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
enqueue_task_fair+0x183/0x16a0 kernel/sched/fair.c:5824
enqueue_task+0x182/0x2b0 kernel/sched/core.c:1977
activate_task kernel/sched/core.c:2005 [inline]
ttwu_do_activate+0x1b5/0x380 kernel/sched/core.c:3614
sched_ttwu_pending+0x272/0x5d0 kernel/sched/core.c:3689
__sysvec_call_function_single+0x98/0x240 arch/x86/kernel/smp.c:248
instr_sysvec_call_function_single arch/x86/kernel/smp.c:243 [inline]
sysvec_call_function_single+0x98/0xc0 arch/x86/kernel/smp.c:243
asm_sysvec_call_function_single+0x16/0x20 arch/x86/include/asm/idtentry.h:684
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:729
Code: bf 48 89 df e8 a6 aa 0a f8 eb b5 e8 4f b0 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d e7 44 54 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffffff8be07dc8 EFLAGS: 000002c6
RAX: 14f6bc6c83fe2300 RBX: ffffffff8bebc3c0 RCX: 14f6bc6c83fe2300
RDX: 0000000000000001 RSI: ffffffff8a0b15c0 RDI: ffffffff8a599340
RBP: ffffffff8be07ef8 R08: dffffc0000000000 R09: ffffed101720765a
R10: ffffed101720765a R11: 1ffff11017207659 R12: ffffffff8d696ea8
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff17d7878
default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
cpuidle_idle_call kernel/sched/idle.c:194 [inline]
do_idle+0x21b/0x5b0 kernel/sched/idle.c:306
cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
start_kernel+0x486/0x530 init/main.c:1140
secondary_startup_64_no_verify+0xb1/0xbb