INFO: task syz.4.852:9595 blocked for more than 145 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.852       state:D stack:27432 pid:9595  tgid:9594  ppid:7324   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776
 sync_bdevs+0x153/0x480 block/bdev.c:1305
 ksys_sync+0xb2/0x150 fs/sync.c:105
 __do_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe869d8f749
RSP: 002b:00007fe86acc4038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fe869fe5fa0 RCX: 00007fe869d8f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fe869fe5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe869fe6038 R14: 00007fe869fe5fa0 R15: 00007ffc32597c68
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e3c96a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e3c96a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8e3c96a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
3 locks held by kworker/1:1/48:
 #0: ffff88801e2e1548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc90000b97c90 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffff8881433a8198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #2: ffff8881433a8198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x52f0 drivers/usb/core/hub.c:5899
5 locks held by kworker/u8:5/254:
2 locks held by getty/5579:
 #0: ffff8880320df0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211
1 lock held by udevd/5963:
 #0: ffff888141741358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:962
1 lock held by syz.4.852/9595:
 #0: ffff888141741358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1305
1 lock held by syz.0.1168/11136:
 #0: ffff888141741358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:962
1 lock held by syz.6.1442/12405:
 #0: ffffffff8e3d4cc0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3816
6 locks held by syz.1.1450/12435:
 #0: ffff888026138270 (&dev->clientlist_mutex){+.+.}-{4:4}, at: drm_client_dev_restore+0xe4/0x2a0 drivers/gpu/drm/drm_client_event.c:113
 #1: ffff8880b8424608 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
 #1: ffff8880b8424608 (psi_seq){-.-.}-{0:0}, at: __schedule+0x19b1/0x6150 kernel/sched/core.c:6857
 #2: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
 #2: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
 #3: ffff8880b8424608 (psi_seq){-.-.}-{0:0}, at: psi_enqueue kernel/sched/stats.h:166 [inline]
 #3: ffff8880b8424608 (psi_seq){-.-.}-{0:0}, at: enqueue_task+0x26d/0x550 kernel/sched/core.c:2096
 #4: ffff88802a526a40 (&l->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #4: ffff88802a526a40 (&l->lock){+.+.}-{3:3}, at: lock_list_lru mm/list_lru.c:68 [inline]
 #4: ffff88802a526a40 (&l->lock){+.+.}-{3:3}, at: lock_list_lru_of_memcg+0x2a9/0x560 mm/list_lru.c:88
 #5: ffffc90004d2fb58 (crtc_ww_class_mutex){+.+.}-{4:4}, at: drm_client_modeset_commit_atomic+0xc4/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1042
2 locks held by syz.1.1450/12436:
 #0: ffff88807ca22488 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #0: ffff88807ca22488 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:661
 #1: ffffffff8e3d4df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311

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

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 10/25/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x133/0x180 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xe66/0x1180 kernel/hung_task.c:515
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12420 Comm: syz.5.1446 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 4b 6d b0 f5 cc
RSP: 0018:ffffc90004bcf2a8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 00000000000000ff RCX: ffffffff821f6d88
RDX: ffff8880294ac980 RSI: ffffffff821f6da0 RDI: 0000000000000007
RBP: ffffea0000f2c100 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffff8880294ad4b0 R12: dffffc0000000000
R13: ffff88804a43e808 R14: ffffea0000f2c100 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c4015f9 CR3: 000000004e67b000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 free_pages_and_swap_cache+0x160/0x4a0 mm/swap_state.c:348
 __tlb_batch_free_encoded_pages+0xf9/0x290 mm/mmu_gather.c:136
 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
 tlb_flush_mmu+0xe9/0x5a0 mm/mmu_gather.c:404
 zap_pte_range mm/memory.c:1893 [inline]
 zap_pmd_range mm/memory.c:1946 [inline]
 zap_pud_range mm/memory.c:1975 [inline]
 zap_p4d_range mm/memory.c:1996 [inline]
 unmap_page_range+0x1e64/0x43c0 mm/memory.c:2017
 unmap_single_vma+0x153/0x240 mm/memory.c:2059
 unmap_vmas+0x218/0x470 mm/memory.c:2101
 exit_mmap+0x1b0/0xb60 mm/mmap.c:1277
 __mmput+0x12a/0x410 kernel/fork.c:1173
 mmput+0x62/0x70 kernel/fork.c:1196
 exit_mm kernel/exit.c:581 [inline]
 do_exit+0x7d7/0x2bd0 kernel/exit.c:959
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
 get_signal+0x2671/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3e6ff8f34b
Code: Unable to access opcode bytes at 0x7f3e6ff8f321.
RSP: 002b:00007f3e70dfaf60 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007f3e6ff8f34b
RDX: 00007f3e70dfbff0 RSI: 0000000080085502 RDI: 0000000000000003
RBP: 00007f3e70013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f3e701e5fa0 R15: 00007ffe850c2d48
 </TASK>