INFO: task syz.0.17:6493 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:25928 pid:6493 tgid:6493 ppid:6370 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5263 [inline] __schedule+0x1836/0x4ed0 kernel/sched/core.c:6871 __schedule_loop kernel/sched/core.c:6953 [inline] schedule+0x165/0x360 kernel/sched/core.c:6968 request_wait_answer fs/fuse/dev.c:585 [inline] __fuse_request_send fs/fuse/dev.c:599 [inline] __fuse_simple_request+0x11d2/0x1bb0 fs/fuse/dev.c:693 fuse_simple_request fs/fuse/fuse_i.h:1251 [inline] fuse_flush+0x5d4/0x800 fs/fuse/file.c:494 filp_flush+0xbd/0x190 fs/open.c:1544 filp_close+0x1d/0x40 fs/open.c:1557 __range_close fs/file.c:790 [inline] __do_sys_close_range fs/file.c:849 [inline] __se_sys_close_range+0x359/0x650 fs/file.c:813 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f386b78ec29 RSP: 002b:00007fff55a1d818 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 0000000000021181 RCX: 00007f386b78ec29 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f386b9d7da0 R08: 0000000000000001 R09: 0000000d55a1db0f R10: 0000001b32120000 R11: 0000000000000246 R12: 00007f386b9d5fac R13: 00007f386b9d5fa0 R14: ffffffffffffffff R15: 00007fff55a1d930 Showing all locks held in the system: 3 locks held by kworker/0:0/9: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236 #1: ffffc900000e7b80 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237 #2: ffff88801f3e4240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0 drivers/net/netdevsim/fib.c:1490 1 lock held by khungtaskd/31: #0: ffffffff8e33d9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33d9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33d9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:7/146: #0: ffff8880b873a718 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639 #1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffffffff8e33d9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e33d9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #2: ffffffff8e33d9c0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline] #2: ffffffff8e33d9c0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x2390 arch/x86/kernel/unwind_orc.c:479 #3: ffffffff8e33d9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #3: ffffffff8e33d9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #3: ffffffff8e33d9c0 (rcu_read_lock){....}-{1:3}, at: xa_find+0x8c/0x2b0 lib/xarray.c:2195 2 locks held by getty/5592: #0: ffff8880314c80a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:19/6746: 1 lock held by syz-executor/6752: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 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:346 [inline] watchdog+0xfb5/0x1000 kernel/hung_task.c:515 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6752 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x90 kernel/kcov.c:320 Code: 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 cc cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 10 bb 92 65 8b 15 98 0b RSP: 0018:ffffc900046bddd8 EFLAGS: 00000293 RAX: ffffffff8b60e855 RBX: 00000000ffffffff RCX: 0000000000000000 RDX: ffff888026eb3d00 RSI: 0000000000000002 RDI: 0000000000000018 RBP: ffffc900046bdf00 R08: ffffc900046bde77 R09: 0000000000000000 R10: ffffc900046bde60 R11: fffff520008d7bcf R12: ffffc900046be1e3 R13: dffffc0000000000 R14: ffffc900046be1e3 R15: 0000000000000002 FS: 0000555582d52500(0000) GS:ffff888125b6f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f65b2a5a6b0 CR3: 00000000783d6000 CR4: 00000000003526f0 Call Trace: number+0xbb1/0xf60 lib/vsprintf.c:572 vsnprintf+0x8e2/0xf00 lib/vsprintf.c:2910 sprintf+0xd9/0x120 lib/vsprintf.c:3109 print_time kernel/printk/printk.c:1357 [inline] info_print_prefix+0x155/0x310 kernel/printk/printk.c:1383 record_print_text+0x154/0x420 kernel/printk/printk.c:1432 printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:3018 console_emit_next_record kernel/printk/printk.c:3083 [inline] console_flush_one_record kernel/printk/printk.c:3215 [inline] console_flush_all+0x514/0xb60 kernel/printk/printk.c:3289 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3359 vprintk_emit+0x4d3/0x5d0 kernel/printk/printk.c:2426 _printk+0xcf/0x120 kernel/printk/printk.c:2451 netdev_info+0x10a/0x160 net/core/dev.c:12967 __dev_set_promiscuity+0x2e8/0x750 net/core/dev.c:9539 __dev_set_rx_mode+0x17c/0x260 net/core/dev.c:-1 dev_uc_add+0xc8/0x120 net/core/dev_addr_lists.c:693 macsec_dev_open+0xd9/0x530 drivers/net/macsec.c:3557 __dev_open+0x441/0x870 net/core/dev.c:1683 __dev_change_flags+0x1da/0x6d0 net/core/dev.c:9727 netif_change_flags+0x88/0x1a0 net/core/dev.c:9790 do_setlink+0xc55/0x41c0 net/core/rtnetlink.c:3158 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:746 __sys_sendto+0x3bd/0x520 net/socket.c:2248 __do_sys_sendto net/socket.c:2255 [inline] __se_sys_sendto net/socket.c:2251 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2251 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9330f90abc Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b RSP: 002b:00007ffdf4eebff0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f9331d04620 RCX: 00007f9330f90abc RDX: 000000000000002c RSI: 00007f9331d04670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffdf4eec044 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f9331d04670 R15: 0000000000000000