INFO: task syz.2.1475:12928 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1475 state:D stack:24288 pid:12928 tgid:12917 ppid:11827 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062
__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: 0033:0x7f7b9db9c799
RSP: 002b:00007f7b9e9ea028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f7b9de16360 RCX: 00007f7b9db9c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f7b9de16360 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b9de163f8 R14: 00007f7b9de16360 R15: 00007ffc6f548d88
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5575:
#0: ffff8880363720a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/6386:
#0: ffff888026054358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
8 locks held by syz-executor/10762:
#0: ffff888035cd40e0 (&type->s_umount_key#105){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888035cd40e0 (&type->s_umount_key#105){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888035cd40e0 (&type->s_umount_key#105){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
#1: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655
#2: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#3: ffff88801d762030 (&l->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline]
#3: ffff88801d762030 (&l->lock){+.+.}-{3:3}, at: lock_list_lru mm/list_lru.c:68 [inline]
#3: ffff88801d762030 (&l->lock){+.+.}-{3:3}, at: lock_list_lru_of_memcg+0x238/0x4c0 mm/list_lru.c:88
#4: ffff88801d762030 (&l->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline]
#4: ffff88801d762030 (&l->lock){+.+.}-{3:3}, at: lock_list_lru mm/list_lru.c:68 [inline]
#4: ffff88801d762030 (&l->lock){+.+.}-{3:3}, at: lock_list_lru_of_memcg+0x238/0x4c0 mm/list_lru.c:88
#5: ffff8880b863a920 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x80b/0x1020 kernel/workqueue.c:-1
#6: ffff88802b6a8a90 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:570 [inline]
#6: ffff88802b6a8a90 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x66/0x1390 kernel/sched/core.c:4130
#7: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655
1 lock held by syz.2.1475/12928:
#0: ffff888026054358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304
8 locks held by syz-executor/14760:
#0: ffff8880344ec420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#0: ffff8880344ec420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 fs/read_write.c:684
#1: ffff8880351a3c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
#2: ffff888025ecbf08 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888025ecbf08 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
#3: ffffffff8f441f48 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff8880282ff0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff8880282ff0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline]
#4: ffff8880282ff0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x860 drivers/base/dd.c:1304
#5: ffff88802131c250 (&devlink->lock_key#21){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1778
#6: ffffffff8fbcd688 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1177
#7: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#7: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
2 locks held by syz.0.1920/14969:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
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:436
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: 14969 Comm: syz.0.1920 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
RIP: 0010:get_page_from_freelist+0x1f28/0x2580 mm/page_alloc.c:3826
Code: fd 4d 89 f7 4d 89 e6 4c 8b 64 24 50 0f 85 a0 01 00 00 48 85 ed 48 be 00 00 00 00 00 fc ff df 0f 85 8d 05 00 00 48 89 5c 24 20 <4c> 89 f0 48 c1 e8 03 0f b6 04 30 84 c0 0f 85 3e 02 00 00 41 8b 1e
RSP: 0018:ffffc90004547520 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: ffff88813fffc300 RSI: dffffc0000000000 RDI: ffff88813fffc300
RBP: 0000000000000000 R08: ffff88813fffd980 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1027fff939 R12: ffff88813fffc300
R13: 0000000000000981 R14: ffffc9000454775c R15: 0000000000000000
FS: 00007ffb81c046c0(0000) GS:ffff888125460000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb6309e7158 CR3: 0000000025efe000 CR4: 0000000000350ef0
Call Trace:
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2484
folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2503
shmem_alloc_folio mm/shmem.c:1930 [inline]
shmem_alloc_and_add_folio+0x445/0xf80 mm/shmem.c:1972
shmem_get_folio_gfp+0x5a9/0x1670 mm/shmem.c:2567
shmem_get_folio mm/shmem.c:2673 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3327
generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4319
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3502
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61d/0xb90 fs/read_write.c:688
ksys_write+0x150/0x270 fs/read_write.c:740
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: 0033:0x7ffb80d5cfce
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007ffb81c03da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ffb81c046c0 RCX: 00007ffb80d5cfce
RDX: 0000000004000000 RSI: 00007ffb76a00000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffb81c03ee0 R14: 00007ffb81c03ea0 R15: 00007ffb76a00000