INFO: task syz.4.4752:27625 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.4.4752 state:D stack:26520 pid:27625 tgid:27624 ppid:27209 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 nfnl_lock net/netfilter/nfnetlink.c:98 [inline] nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 nfnetlink_rcv+0x2c0/0x27b0 net/netfilter/nfnetlink.c:669 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 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: 0033:0x7fdac839c819 RSP: 002b:00007fdac9192028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fdac8615fa0 RCX: 00007fdac839c819 RDX: 0000000004000820 RSI: 0000200000000080 RDI: 0000000000000005 RBP: 00007fdac8432c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdac8616038 R14: 00007fdac8615fa0 R15: 00007fdac873fa48 INFO: task syz.7.4771:27769 blocked for more than 145 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.4771 state:D stack:25352 pid:27769 tgid:27758 ppid:26448 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 nfnl_lock net/netfilter/nfnetlink.c:98 [inline] nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 nfnetlink_rcv+0x2c0/0x27b0 net/netfilter/nfnetlink.c:669 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 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: 0033:0x7f43c199c819 RSP: 002b:00007f43c2874028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f43c1c16180 RCX: 00007f43c199c819 RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000009 RBP: 00007f43c1a32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f43c1c16218 R14: 00007f43c1c16180 R15: 00007f43c1d3fa48 INFO: task syz.8.4782:27831 blocked for more than 146 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.4782 state:D stack:26520 pid:27831 tgid:27830 ppid:26457 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 nfnl_lock net/netfilter/nfnetlink.c:98 [inline] nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 nfnetlink_rcv+0x2c0/0x27b0 net/netfilter/nfnetlink.c:669 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 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: 0033:0x7f41f079c819 RSP: 002b:00007f41f172c028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f41f0a15fa0 RCX: 00007f41f079c819 RDX: 0000000000000080 RSI: 00002000000002c0 RDI: 0000000000000004 RBP: 00007f41f0832c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f41f0a16038 R14: 00007f41f0a15fa0 R15: 00007f41f0b3fa48 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5579: #0: ffff88803798a0a0 (&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 syz.1.3244/19012: 4 locks held by kworker/u8:2/24152: #0: ffff88801f6e7948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801f6e7948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000644fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000644fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff888035e2a0e0 (&type->s_umount_key#33){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff888035e28c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #3: ffff888035e28c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1814 [inline] #3: ffff888035e28c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3028 1 lock held by syz.4.4752/27625: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.7.4771/27769: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.8.4782/27831: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.2.4796/28065: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.1.4852/28474: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.3.4922/28863: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.3.4922/28865: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.5.4924/28873: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.0.4943/29022: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.6.4965/29294: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.4.4971/29339: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.9.4991/29475: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 1 lock held by syz.3.5059/29867: #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9a7b4cf8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:295 2 locks held by dhcpcd/30033: #0: ffff888089f82260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1709 [inline] #0: ffff888089f82260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3198 #1: ffffffff8e7648b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e7648b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 2 locks held by dhcpcd/30034: #0: ffff88804c15c260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1709 [inline] #0: ffff88804c15c260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3198 #1: ffffffff8e7648b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e7648b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(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: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:436 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:update_curr+0x501/0x780 kernel/sched/fair.c:1328 Code: 40 e8 b3 fd 96 00 4c 8b 73 78 4c 8d bb 88 00 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 92 fd 96 00 4d 3b 37 <78> 2a 48 8b 7c 24 28 e8 83 03 fb ff 49 83 c4 60 4c 89 e0 48 c1 e8 RSP: 0018:ffffffff8e407ae0 EFLAGS: 00000016 RAX: 1ffff11003ed3b91 RBX: ffff88801f69dc00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff RBP: ffff88801f69dc28 R08: ffff8880b8628283 R09: 1ffff110170c5050 R10: dffffc0000000000 R11: ffffed10170c5051 R12: ffff8880b873aec0 R13: dffffc0000000000 R14: 0000009575cd5787 R15: ffff88801f69dc88 FS: 0000000000000000(0000) GS:ffff888125454000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556993f454b0 CR3: 0000000076f78000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000003e4f DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: pick_task_fair+0xb7/0x2a0 kernel/sched/fair.c:8958 pick_task kernel/sched/core.c:5997 [inline] pick_next_task kernel/sched/core.c:6134 [inline] __schedule+0x3581/0x52d0 kernel/sched/core.c:6852 schedule_idle+0x51/0x90 kernel/sched/core.c:7034 do_idle+0x58a/0x5f0 kernel/sched/idle.c:381 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 rest_init+0x2de/0x300 init/main.c:760 start_kernel+0x385/0x3d0 init/main.c:1210 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147