INFO: task syz.4.104:6513 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.104 state:D stack:26464 pid:6513 tgid:6506 ppid:5838 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
sync_bdevs+0x27e/0x470 block/bdev.c:1304
ksys_sync fs/sync.c:105 [inline]
__ia32_sys_sync+0xc5/0x120 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa0bb59bf79
RSP: 002b:00007fa0bc440028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fa0bb816180 RCX: 00007fa0bb59bf79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fa0bb816180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa0bb816218 R14: 00007fa0bb816180 R15: 00007ffcacd45168
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:4/77:
#0: ffff88801c2ae948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffff8880b8726118 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x8ee/0xf30 kernel/time/timer.c:1117
2 locks held by getty/5581:
#0: ffff8880373b10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/5824:
#0: ffff888026742358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by udevd/5834:
3 locks held by kworker/1:6/5916:
#0: ffff88801b06b548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc90004307c40 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8e766440 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
4 locks held by udevd/6073:
#0: ffff888075a74668 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183
#1: ffff88806865d088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffff8880513ad2d8 (kn->active#28){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880513ad2d8 (kn->active#28){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
#3: ffff888073993198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline]
#3: ffff888073993198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by syz.4.104/6513:
#0: ffff888026742358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304
5 locks held by kworker/0:7/8162:
1 lock held by syz.6.601/9132:
#0: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#0: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
4 locks held by dhcpcd-run-hook/9189:
#0: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655
#1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffff888034490198 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline]
#2: ffff888034490198 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: handle_pte_fault mm/memory.c:6325 [inline]
#2: ffff888034490198 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __handle_mm_fault mm/memory.c:6455 [inline]
#2: ffff888034490198 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: handle_mm_fault+0x146c/0x3310 mm/memory.c:6624
#3: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655
1 lock held by sed/9192:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
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: 9197 Comm: sed Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__kasan_check_byte+0x6/0x40 mm/kasan/common.c:572
Code: f6 5b 41 5c 41 5e 41 5f e9 17 fa ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 41 56 <53> 48 89 f3 49 89 fe e8 8e 15 00 00 84 c0 75 16 be 01 00 00 00 4c
RSP: 0000:ffffc90002f37190 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff823a22cd RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff81768a62 RDI: ffffffff8e7602e0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90002f37338 R11: ffffffff81b0c580 R12: 0000000000000002
R13: ffffffff8e7602e0 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125460000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efca345dbe8 CR3: 0000000059fe0000 CR4: 00000000003526f0
Call Trace:
kasan_check_byte include/linux/kasan.h:402 [inline]
lock_acquire+0x79/0x2e0 kernel/locking/lockdep.c:5842
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2485
folio_alloc_mpol_noprof mm/mempolicy.c:2504 [inline]
vma_alloc_folio_noprof+0xea/0x210 mm/mempolicy.c:2539
folio_prealloc mm/memory.c:-1 [inline]
wp_page_copy mm/memory.c:3780 [inline]
do_wp_page+0x1204/0x5a00 mm/memory.c:4241
handle_pte_fault mm/memory.c:6333 [inline]
__handle_mm_fault mm/memory.c:6455 [inline]
handle_mm_fault+0x1520/0x3310 mm/memory.c:6624
do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7efca3712418
Code: fe ff ff 0f 1f 80 00 00 00 00 48 85 f6 0f 84 af 00 00 00 41 f6 85 56 03 00 00 20 0f 85 a1 00 00 00 49 8b 45 60 48 85 c0 74 04 <48> 01 70 08 49 8b 45 58 48 85 c0 74 04 48 01 70 08 49 8b 45 68 48
RSP: 002b:00007ffd3dcacea0 EFLAGS: 00010202
RAX: 00007efca345dbe0 RBX: 0000000000000030 RCX: 00007efca3701b60
RDX: 00007efca345dd30 RSI: 00007efca344e000 RDI: 000000006fffffff
RBP: 00007ffd3dcacff0 R08: 0000000000000006 R09: 00000000effffef5
R10: 0000000070000029 R11: 00007ffd3dcad0d8 R12: 00007ffd3dcacd50
R13: 00007efca3701b20 R14: 00007ffd3dcad090 R15: 00007efca345e010