INFO: task syz-executor:5824 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-executor state:D stack:21320 pid:5824 tgid:5824 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x169e/0x54f0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 fuse_chan_wait_aborted+0x15b/0x250 fs/fuse/dev.c:2212 fuse_conn_destroy+0x1e7/0x3e0 fs/fuse/inode.c:1969 fuse_sb_destroy fs/fuse/inode.c:1988 [inline] fuse_kill_sb_anon+0x1ef/0x270 fs/fuse/inode.c:2001 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f99f263da57 RSP: 002b:00007fffea258d38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f99f26d2048 RCX: 00007f99f263da57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffea258df0 RBP: 00007fffea258df0 R08: 00007fffea259df0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffea259e80 R13: 00007f99f26d2048 R14: 0000000000028fb3 R15: 00007fffea259ec0 Showing all locks held in the system: 17 locks held by ksoftirqd/0/15: #0: ffffffff8e25f280 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_list_internal+0x501/0xcf0 net/core/dev.c:6428 #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: ip_local_deliver_finish+0x2ae/0x6f0 net/ipv4/ip_input.c:240 #4: ffff88803cb6f0e0 (slock-AF_INET/1){+...}-{3:3}, at: tcp_v4_rcv+0x25d4/0x2ff0 net/ipv4/tcp_ipv4.c:2242 #5: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #5: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #5: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #5: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock_nested+0x1de/0x3f0 kernel/locking/spinlock_rt.c:65 #6: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #6: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #6: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __ip_queue_xmit+0x5c/0x1bb0 net/ipv4/ip_output.c:477 #7: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #7: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #7: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: ip_output+0x5b/0x450 net/ipv4/ip_output.c:433 #8: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #8: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #8: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x3c2/0x10b0 net/ipv4/ip_output.c:230 #9: ffffffff8e25f280 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #10: ffffffff8e3c8160 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #10: ffffffff8e3c8160 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline] #10: ffffffff8e3c8160 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b3/0x3900 net/core/dev.c:4792 #11: ffff88803e34a328 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:205 [inline] #11: ffff88803e34a328 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4197 [inline] #11: ffff88803e34a328 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{3:3}, at: __dev_queue_xmit+0x1110/0x3900 net/core/dev.c:4832 #12: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #12: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #12: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_trylock kernel/locking/spinlock_rt.c:110 [inline] #12: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x10c/0x2b0 kernel/locking/spinlock_rt.c:118 #13: ffff88801c711198 (_xmit_ETHER#2){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #13: ffff88801c711198 (_xmit_ETHER#2){+...}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4779 [inline] #13: ffff88801c711198 (_xmit_ETHER#2){+...}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370 #14: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #14: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #14: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #14: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #15: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #15: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #15: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: dev_queue_xmit_nit+0x2d/0xad0 net/core/dev.c:2555 #16: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #16: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #16: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline] #16: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495 4 locks held by pr/legacy/17: #0: ffffffff8e3ba3a0 (console_lock){+.+.}-{0:0}, at: legacy_kthread_func+0x1a3/0x250 kernel/printk/printk.c:3711 #1: ffffffff8e2a1c98 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:305 [inline] #1: ffffffff8e2a1c98 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:428 [inline] #1: ffffffff8e2a1c98 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:291 [inline] #1: ffffffff8e2a1c98 (console_srcu){....}-{0:0}, at: console_flush_one_record+0xfa/0xb90 kernel/printk/printk.c:3246 #2: ffffffff9a02f858 (&port_lock_key){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffffffff9a02f858 (&port_lock_key){+.+.}-{3:3}, at: uart_port_lock_irqsave include/linux/serial_core.h:717 [inline] #2: ffffffff9a02f858 (&port_lock_key){+.+.}-{3:3}, at: serial8250_console_write+0x179/0x1b90 drivers/tty/serial/8250/8250_port.c:3316 #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 1 lock held by khungtaskd/39: #0: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 2 locks held by getty/5578: #0: ffff8880373fd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cb62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 4 locks held by syz-executor/5811: #0: ffff88803cb6f198 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88803cb6f198 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x21/0x50 net/ipv4/tcp.c:1454 #1: ffffffff8e25f280 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #3: ffff88803cb6f0e0 (slock-AF_INET){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock_rt.h:90 [inline] #3: ffff88803cb6f0e0 (slock-AF_INET){+...}-{3:3}, at: lock_sock_nested+0x7e/0x130 net/core/sock.c:3802 1 lock held by syz-executor/5824: #0: ffff8880396e80d0 (&type->s_umount_key#59){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880396e80d0 (&type->s_umount_key#59){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880396e80d0 (&type->s_umount_key#59){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 1 lock held by syz.3.468/7350: #0: ffff8880396e80d0 (&type->s_umount_key#59){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880396e80d0 (&type->s_umount_key#59){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz-executor/7547: #0: ffff888027b4e0d0 (&type->s_umount_key#60){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888027b4e0d0 (&type->s_umount_key#60){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888027b4e0d0 (&type->s_umount_key#60){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 1 lock held by syz.7.1047/9072: #0: ffff88805ecb4538 (&runtime->oss.params_lock){+.+.}-{4:4}, at: snd_pcm_oss_read3+0x3d8/0x5f0 sound/core/oss/pcm_oss.c:1290 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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:162 [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:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 17 Comm: pr/legacy Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401 Code: e8 3e 9c 7d fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ef 12 e7 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 ca fa fd 05 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900001679d0 EFLAGS: 00000202 RAX: 1ffffffff3405f00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff9a02fb10 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff85475d10 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff9a02f880 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125a62000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000008000 CR3: 000000003556a000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1970 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline] serial8250_console_write+0x120d/0x1b90 drivers/tty/serial/8250/8250_port.c:3357 console_emit_next_record kernel/printk/printk.c:3163 [inline] console_flush_one_record+0x68b/0xb90 kernel/printk/printk.c:3269 legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245