INFO: task syz.0.20:6017 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.20 state:D stack:25400 pid:6017 tgid:6016 ppid:5802 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 percpu_rwsem_wait+0x2e6/0x330 kernel/locking/percpu-rwsem.c:164 __percpu_down_read+0xfc/0x140 kernel/locking/percpu-rwsem.c:180 percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_write+0x18e/0x1c0 include/linux/fs/super.h:125 mnt_want_write+0x41/0x90 fs/namespace.c:499 filename_create+0x14f/0x360 fs/namei.c:4872 do_mknodat+0x181/0x620 fs/namei.c:5026 __do_sys_mknod fs/namei.c:5076 [inline] __se_sys_mknod fs/namei.c:5074 [inline] __x64_sys_mknod+0x8c/0xa0 fs/namei.c:5074 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd82286f749 RSP: 002b:00007fd820ace038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007fd822ac5fa0 RCX: 00007fd82286f749 RDX: 0000000000000000 RSI: 0000000000001000 RDI: 00002000000000c0 RBP: 00007fd8228f3f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd822ac6038 R14: 00007fd822ac5fa0 R15: 00007ffdd25790b8 INFO: task syz.0.20:6030 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.20 state:D stack:25640 pid:6030 tgid:6016 ppid:5802 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 percpu_rwsem_wait+0x2e6/0x330 kernel/locking/percpu-rwsem.c:164 __percpu_down_read+0xfc/0x140 kernel/locking/percpu-rwsem.c:180 percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_write+0x18e/0x1c0 include/linux/fs/super.h:125 mnt_want_write+0x41/0x90 fs/namespace.c:499 open_last_lookups fs/namei.c:4529 [inline] path_openat+0xae9/0x3df0 fs/namei.c:4784 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_open fs/open.c:1444 [inline] __se_sys_open fs/open.c:1440 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1440 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd82286f749 RSP: 002b:00007fd820aad038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fd822ac6090 RCX: 00007fd82286f749 RDX: 0000000000000000 RSI: 0000000000143142 RDI: 0000200000000100 RBP: 00007fd8228f3f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd822ac6128 R14: 00007fd822ac6090 R15: 00007ffdd25790b8 INFO: task syz.0.20:6036 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.20 state:D stack:27096 pid:6036 tgid:6016 ppid:5802 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 percpu_rwsem_wait+0x2e6/0x330 kernel/locking/percpu-rwsem.c:164 __percpu_down_read+0xfc/0x140 kernel/locking/percpu-rwsem.c:180 percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_write+0x18e/0x1c0 include/linux/fs/super.h:125 mnt_want_write+0x41/0x90 fs/namespace.c:499 do_unlinkat+0x133/0x570 fs/namei.c:5416 __do_sys_unlink fs/namei.c:5474 [inline] __se_sys_unlink fs/namei.c:5472 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:5472 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd82286f749 RSP: 002b:00007fd820a8c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007fd822ac6180 RCX: 00007fd82286f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007fd8228f3f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd822ac6218 R14: 00007fd822ac6180 R15: 00007ffdd25790b8 Showing all locks held in the system: 2 locks held by kworker/u8:1/13: #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90000127bc0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000127bc0 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 1 lock held by khungtaskd/38: #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/1:2/985: #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc900046afbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900046afbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8e8a58b8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 5 locks held by kworker/u8:16/3815: 3 locks held by kworker/u8:17/3917: #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000da67bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000da67bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8e8a58b8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 4 locks held by kworker/u8:20/4162: #0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000e137bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000e137bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8e898780 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7b0 net/core/net_namespace.c:670 #3: ffffffff8e8a58b8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8e8a58b8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:248 1 lock held by dhcpcd/5467: #0: ffffffff8e8a58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8e8a58b8 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b20 net/ipv4/devinet.c:1120 2 locks held by getty/5559: #0: ffff88814e1850a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5800: #0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: read_lock include/linux/rwlock_rt.h:37 [inline] #0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: __do_wait+0xe1/0x740 kernel/exit.c:1672 8 locks held by kworker/0:4/5873: 1 lock held by udevd/5926: 1 lock held by syz.0.20/6017: #0: ffff888062b80480 (sb_writers#16){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 1 lock held by syz.0.20/6030: #0: ffff888062b80480 (sb_writers#16){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 1 lock held by syz.0.20/6036: #0: ffff888062b80480 (sb_writers#16){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 1 lock held by syz-executor/7124: 1 lock held by syz-executor/8131: #0: ffffffff8e8a58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8e8a58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8e8a58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071 2 locks held by kworker/u8:24/8140: #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000e027bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000e027bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 1 lock held by syz-executor/8167: #0: ffffffff8e8a58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8e8a58b8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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: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+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 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: 8184 Comm: syz.8.314 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:mark_lock+0xd/0x190 kernel/locking/lockdep.c:4722 Code: 8b 2c 24 e9 b6 fd ff ff 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 8b 46 20 <89> c1 81 e1 00 00 03 00 83 f9 01 bb 09 00 00 00 83 db 00 83 fa 08 RSP: 0000:ffffc9000e057b28 EFLAGS: 00000002 RAX: 0000000000058867 RBX: ffff88801d7b8000 RCX: ffffffff92624408 RDX: 0000000000000008 RSI: ffff88801d7b8b90 RDI: ffff88801d7b8000 RBP: 0000000000000000 R08: ffffffff82080137 R09: ffff88803764ca88 R10: 0000000000000000 R11: fffff52001c0af98 R12: 0000000000000867 R13: ffff88801d7b8b90 R14: ffff88801d7b8000 R15: ffff88801d7b8b90 FS: 00007f16c90ce6c0(0000) GS:ffff888126def000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f16c1157000 CR3: 000000003e9fc000 CR4: 00000000003526f0 Call Trace: mark_usage kernel/locking/lockdep.c:4674 [inline] __lock_acquire+0x6b6/0x2cf0 kernel/locking/lockdep.c:5191 reacquire_held_locks+0x104/0x190 kernel/locking/lockdep.c:5385 __lock_release kernel/locking/lockdep.c:5574 [inline] lock_release+0x19a/0x3b0 kernel/locking/lockdep.c:5889 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] lock_vma_under_rcu+0x3c2/0x4a0 mm/mmap_lock.c:278 do_user_addr_fault+0x2d9/0x1380 arch/x86/mm/fault.c:1327 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x71/0xd0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f16cad309e6 Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01 RSP: 002b:00007f16c90cd4a0 EFLAGS: 00010206 RAX: 00000000004a9001 RBX: 00007f16c90cd540 RCX: 0000000000000038 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f16c90cd5e0 RBP: 0000000000000102 R08: 00007f16c0cae000 R09: 00000000004a9000 R10: 0000000000000000 R11: 00007f16c90cd550 R12: 0000000000000001 R13: 00007f16caf0fc40 R14: 0000000000000000 R15: 00007f16c90cd5e0