INFO: task syz.3.1613:13390 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.3.1613 state:D stack:27176 pid:13390 tgid:13389 ppid:11218 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: 0033:0x7f964f79bf79 RSP: 002b:00007f9650699028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f964fa15fa0 RCX: 00007f964f79bf79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f964fa15fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f964fa16038 R14: 00007f964fa15fa0 R15: 00007fff5dbc3bb8 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #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 1 lock held by khungtaskd/31: #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/u8:9/1149: #0: ffff88801c2ae948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254 #1: ffffc90004fcfc40 (net_cleanup_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 6 locks held by kworker/u8:10/1160: 2 locks held by getty/5582: #0: ffff888037a920a0 (&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/5841: #0: ffff8880274fd358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961 1 lock held by syz.3.1613/13390: #0: ffff8880274fd358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304 5 locks held by syz-executor/14186: ============================================= NMI backtrace for cpu 0 CPU: 0 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 02/12/2026 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 15825 Comm: syz.6.2142 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:native_apic_msr_write+0x3b/0x50 arch/x86/include/asm/apic.h:209 Code: 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 66 90 cc cc cc cc cc 89 f6 31 d2 e9 a6 9a 76 03 66 0f 1f 44 00 00 90 RSP: 0018:ffffc90000a08e48 EFLAGS: 00000046 RAX: 000000000006c93e RBX: ffff8880b8723e40 RCX: 0000000000000838 RDX: 0000000000000000 RSI: 000000000006c93e RDI: 0000000000000838 RBP: 0000000000000000 R08: ffffffff81b2d065 R09: ffffffff9a2ba508 R10: 0000000000000003 R11: ffffffff8173d750 R12: 0000000010006d0d R13: dffffc0000000000 R14: 000000000006c93e R15: 0000000000000020 FS: 00007fc183b276c0(0000) GS:ffff888125560000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000029000 CR3: 000000005ceca000 CR4: 00000000003526f0 Call Trace: apic_write arch/x86/include/asm/apic.h:405 [inline] lapic_next_event+0x11/0x20 arch/x86/kernel/apic/apic.c:418 clockevents_program_event+0x1c9/0x350 kernel/time/clockevents.c:334 hrtimer_interrupt+0xb08/0x1010 kernel/time/hrtimer.c:1924 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x460 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:finish_task_switch+0x245/0x920 kernel/sched/core.c:5152 Code: 00 00 48 85 db 0f 85 e8 01 00 00 e9 56 05 00 00 4c 8b 75 d0 49 83 c4 48 4c 89 e7 e8 a5 8c 1b 0a e8 10 84 38 00 fb 4c 8b 65 c0 <49> 8d bc 24 30 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc90003877538 EFLAGS: 00000206 RAX: 000000000000909f RBX: 0000000000000000 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8def38f2 RDI: ffffffff8c27ab00 RBP: ffffc90003877590 R08: ffffffff901195b7 R09: 1ffffffff20232b6 R10: dffffc0000000000 R11: fffffbfff20232b7 R12: ffff88805f601e40 R13: dffffc0000000000 R14: ffff888020ebbc80 R15: ffff8880b873b918 context_switch kernel/sched/core.c:5298 [inline] __schedule+0x158d/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153 rdmsr_safe_on_cpu+0x18e/0x2b0 arch/x86/lib/msr-smp.c:181 msr_read+0x150/0x250 arch/x86/kernel/msr.c:66 vfs_read+0x20c/0xa70 fs/read_write.c:572 ksys_read+0x150/0x270 fs/read_write.c:717 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: 0033:0x7fc182b9bf79 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc183b27028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fc182e15fa0 RCX: 00007fc182b9bf79 RDX: 0000000000018ff8 RSI: 000020000001e580 RDI: 0000000000000003 RBP: 00007fc182c327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc182e16038 R14: 00007fc182e15fa0 R15: 00007ffd262ee358