INFO: task syz-executor:9732 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21896 pid:9732 tgid:9732 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547 genl_lock net/netlink/genetlink.c:35 [inline] genl_op_lock net/netlink/genetlink.c:60 [inline] genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x843/0xa10 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 __sys_sendto+0x3c7/0x520 net/socket.c:2228 __do_sys_sendto net/socket.c:2235 [inline] __se_sys_sendto net/socket.c:2231 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2231 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f96120c0a7c RSP: 002b:00007ffc801c3a30 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f9612e14620 RCX: 00007f96120c0a7c RDX: 0000000000000020 RSI: 00007f9612e14670 RDI: 0000000000000005 RBP: 0000000000000000 R08: 00007ffc801c3a84 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005 R13: 00007ffc801c3ad8 R14: 00007f9612e14670 R15: 0000000000000000 INFO: task syz.2.1262:10112 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1262 state:D stack:26856 pid:10112 tgid:10109 ppid:5836 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547 genl_lock net/netlink/genetlink.c:35 [inline] genl_op_lock net/netlink/genetlink.c:60 [inline] genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x843/0xa10 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 __sys_sendto+0x3c7/0x520 net/socket.c:2228 __do_sys_sendto net/socket.c:2235 [inline] __se_sys_sendto net/socket.c:2231 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2231 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8973cd0a7c RSP: 002b:00007f8971f2cec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f8971f2cfc0 RCX: 00007f8973cd0a7c RDX: 0000000000000020 RSI: 00007f8971f2d010 RDI: 0000000000000005 RBP: 0000000000000000 R08: 00007f8971f2cf14 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005 R13: 00007f8971f2cf68 R14: 00007f8971f2d010 R15: 0000000000000000 Showing all locks held in the system: 4 locks held by kworker/u8:2/37: 1 lock held by khungtaskd/39: #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:3/57: #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000123fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000123fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd1f38 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by kworker/u8:6/1100: 2 locks held by getty/5596: #0: ffff88823bf720a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/9732: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 3 locks held by syz.6.1256/10089: 2 locks held by syz.2.1262/10112: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz-executor/10198: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz-executor/10240: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz-executor/10241: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz.4.1302/10273: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz.4.1302/10274: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz-executor/10316: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz-executor/10360: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz-executor/10466: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz-executor/10500: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz-executor/10502: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz-executor/10522: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz-executor/10531: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 2 locks held by syz-executor/10540: #0: ffffffff8ed37f40 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed37d38 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 1 lock held by syz-executor/10550: #0: ffffffff8ecd1f38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ecd1f38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ecd1f38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 1 lock held by syz-executor/10552: #0: ffffffff8ecd1f38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ecd1f38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ecd1f38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 53 b2 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 e3 11 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8d607d80 EFLAGS: 000002c6 RAX: f4afacd291c2ce00 RBX: ffffffff81954f18 RCX: f4afacd291c2ce00 RDX: 0000000000000001 RSI: ffffffff8d038501 RDI: ffffffff8b620c80 RBP: ffffffff8d607eb8 R08: ffff8880b883341b R09: 1ffff11017106683 R10: dffffc0000000000 R11: ffffed1017106684 R12: ffffffff8f1d4530 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1ae0620 FS: 0000000000000000(0000) GS:ffff8881268c2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa0d8d02f80 CR3: 000000005a312000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000006800 DR2: 0000000000009951 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:744 start_kernel+0x3a9/0x410 init/main.c:1097 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147