INFO: task syz.3.367:7653 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.3.367 state:D stack:27448 pid:7653 tgid:7651 ppid:5836 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 sync_bdevs+0x27e/0x470 block/bdev.c:1305 ksys_sync+0xb9/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4a4958f749 RSP: 002b:00007f4a4a43b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f4a497e6090 RCX: 00007f4a4958f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f4a497e6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4a497e6128 R14: 00007f4a497e6090 R15: 00007ffc59806bc8 Showing all locks held in the system: 1 lock held by rcu_exp_gp_kthr/18: #0: ffff8880b863ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647 1 lock held by khungtaskd/31: #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5585: #0: ffff88814c7b80a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211 1 lock held by udevd/6049: #0: ffff8880259bd358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962 1 lock held by syz.3.367/7653: #0: ffff8880259bd358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1305 1 lock held by syz.5.786/9506: #0: ffff888032390ee0 (sk_lock-AF_SMC){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline] #0: ffff888032390ee0 (sk_lock-AF_SMC){+.+.}-{0:0}, at: smc_sendmsg+0x52/0x4d0 net/smc/af_smc.c:2791 2 locks held by syz.4.791/9521: 1 lock held by syz.6.797/9546: #0: ffffffff8e144d00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3816 4 locks held by syz.0.798/9548: #0: ffff88804e8cde08 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff88804e8cde08 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x89/0x250 net/socket.c:665 #1: ffffffff8f578530 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379 #2: ffff888028b814d8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nft_rcv_nl_event+0x116/0x640 net/netfilter/nf_tables_api.c:12135 #3: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #3: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956 ============================================= 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: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/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+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:363 [inline] watchdog+0xe40/0xe90 kernel/hung_task.c:557 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7888 Comm: syz-executor 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:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x17/0xb0 kernel/rcu/tree.c:751 Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 65 ff 05 90 18 f8 10 e8 7b 36 b6 09 89 c3 <83> f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 8d bb RSP: 0018:ffffc9001c6679a0 EFLAGS: 00000086 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 550c82f1a529d300 RDX: 0000000000000000 RSI: ffffffff8be07940 RDI: ffffffff8be07900 RBP: ffffffff81af64e5 R08: 0000000000000001 R09: 0000000000000000 R10: 000000000000000b R11: 0000000000000000 R12: 0000000000000002 R13: ffffffff99af4508 R14: 0000000000000000 R15: 0000000000000001 FS: 0000555594a3c500(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000013c0 CR3: 0000000028064000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 0000000000000007 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x5f/0x340 kernel/locking/lockdep.c:5831 seqcount_lockdep_reader_access+0xcf/0x1c0 include/linux/seqlock.h:72 ktime_get+0x45/0x200 kernel/time/timekeeping.c:824 __hrtimer_start_range_ns kernel/time/hrtimer.c:1249 [inline] hrtimer_start_range_ns+0x339/0x1080 kernel/time/hrtimer.c:1322 hrtimer_start_expires include/linux/hrtimer.h:273 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:2039 [inline] do_nanosleep+0x18c/0x610 kernel/time/hrtimer.c:2113 hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2163 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline] __se_sys_clock_nanosleep+0x339/0x390 kernel/time/posix-timers.c:1375 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f136d7c2005 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 54 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f 55 ff ff 48 8b 04 24 48 83 c4 28 f7 d8 RSP: 002b:00007ffdffb4d000 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00000000000000ee RCX: 00007f136d7c2005 RDX: 00007ffdffb4d040 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffdffb4d0ac R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388 R13: 00000000000927c0 R14: 000000000005a113 R15: 00007ffdffb4d100