INFO: task syz.0.23:6072 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.23 state:D stack:27496 pid:6072 tgid:6070 ppid:5846 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119 rwsem_down_read_slowpath+0x6d9/0x940 kernel/locking/rwsem.c:1114 __down_read_common kernel/locking/rwsem.c:1291 [inline] __down_read kernel/locking/rwsem.c:1304 [inline] down_read+0x99/0x2e0 kernel/locking/rwsem.c:1570 mmap_read_lock include/linux/mmap_lock.h:592 [inline] exit_mm+0x73/0x250 kernel/exit.c:557 do_exit+0x8b9/0x2490 kernel/exit.c:962 do_group_exit+0x21b/0x2d0 kernel/exit.c:1116 get_signal+0x1284/0x1330 kernel/signal.c:3035 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5089d9c799 RSP: 002b:00007f508abd9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: 000000000000000b RBX: 00007f508a016090 RCX: 00007f5089d9c799 RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007f5089e32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f508a016128 R14: 00007f508a016090 R15: 00007ffe0d43cd68 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:4/58: #0: ffff8880337ad940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261 #1: ffffc900015f7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262 #2: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4198 2 locks held by dhcpcd/5509: #0: ffff88805a5f46e8 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe4/0xe80 net/netlink/af_netlink.c:2267 #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826 2 locks held by getty/5601: #0: ffff8880387b20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 6 locks held by kworker/u8:11/6069: #0: ffff88801c2b6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261 #1: ffffc900050f7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262 #2: ffffffff8fbc6d68 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1705 #4: ffff888059660780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6443 [inline] #4: ffff888059660780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_netdev_notifier_call+0x1a8/0x1470 net/wireless/core.c:1598 #5: ffffffff8e7638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #5: ffffffff8e7638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.0.23/6072: #0: ffff88807d2ce738 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff88807d2ce738 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0x73/0x250 kernel/exit.c:557 3 locks held by udevd/6661: 2 locks held by syz-executor/6769: #0: ffffffff901280e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff901280e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff901280e8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 2 locks held by syz-executor/6920: #0: ffffffff90128218 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff90128218 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff90128218 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 1 lock held by syz.2.213/6988: #0: ffffffff8e7637b8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 1 lock held by dhcpcd/6994: #0: ffff88804a058260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88804a058260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe70 net/packet/af_packet.c:3197 2 locks held by dhcpcd/6996: #0: ffff88804f20a260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88804f20a260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe70 net/packet/af_packet.c:3197 #1: ffffffff8e7638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e7638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by dhcpcd/6997: #0: ffff88804f208260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88804f208260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe70 net/packet/af_packet.c:3197 1 lock held by dhcpcd/6998: #0: ffff88804f20e260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88804f20e260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe70 net/packet/af_packet.c:3197 1 lock held by dhcpcd/6999: #0: ffff88804f20c260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88804f20c260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe70 net/packet/af_packet.c:3197 1 lock held by dhcpcd/7000: #0: ffff88804f07a260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88804f07a260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe70 net/packet/af_packet.c:3197 ============================================= 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 02/12/2026 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+0x1002/0x1060 kernel/hung_task.c:561 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: ed 6a 02 e9 d3 f1 02 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 b3 e1 14 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 00000242 RAX: 00000000007abddf RBX: ffffffff819b946a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8df3af0d RDI: ffffffff8c284e00 RBP: ffffc90000197f10 R08: ffff8880b873399b R09: 1ffff110170e6733 R10: dffffc0000000000 R11: ffffed10170e6734 R12: 0000000000000001 R13: 1ffff11003c54000 R14: 0000000000000001 R15: 1ffff11003c54000 FS: 0000000000000000(0000) GS:ffff888125535000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb4873e92f8 CR3: 000000001bbca000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147