INFO: task syz.0.300:8045 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.300 state:D stack:28952 pid:8045 tgid:8018 ppid:5800 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1072 [inline] __start_dirop fs/namei.c:2873 [inline] start_dirop fs/namei.c:2884 [inline] filename_create+0x200/0x370 fs/namei.c:4888 do_symlinkat+0x135/0x3c0 fs/namei.c:5543 __do_sys_symlink fs/namei.c:5576 [inline] __se_sys_symlink fs/namei.c:5574 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:5574 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb6afe3acb9 RSP: 002b:00007fb6ae075028 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007fb6b00b6090 RCX: 00007fb6afe3acb9 RDX: 0000000000000000 RSI: 0000200000000980 RDI: 0000200000000440 RBP: 00007fb6afea8bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb6b00b6128 R14: 00007fb6b00b6090 R15: 00007ffcdfa60de8 INFO: task syz.0.300:8048 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.300 state:D stack:28248 pid:8048 tgid:8018 ppid:5800 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1027 [inline] open_last_lookups fs/namei.c:4546 [inline] path_openat+0xb65/0x3e70 fs/namei.c:4793 do_filp_open+0x22d/0x490 fs/namei.c:4823 do_sys_openat2+0x12f/0x220 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_creat fs/open.c:1514 [inline] __se_sys_creat fs/open.c:1508 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1508 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb6afe3acb9 RSP: 002b:00007fb6ae054028 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007fb6b00b6180 RCX: 00007fb6afe3acb9 RDX: 0000000000000000 RSI: 00000000000000a1 RDI: 0000200000000100 RBP: 00007fb6afea8bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb6b00b6218 R14: 00007fb6b00b6180 R15: 00007ffcdfa60de8 INFO: task syz.0.300:8049 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.300 state:D stack:28840 pid:8049 tgid:8018 ppid:5800 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1072 [inline] __start_dirop fs/namei.c:2873 [inline] start_dirop fs/namei.c:2884 [inline] filename_create+0x200/0x370 fs/namei.c:4888 do_mkdirat+0xd2/0x4c0 fs/namei.c:5165 __do_sys_mkdirat fs/namei.c:5195 [inline] __se_sys_mkdirat fs/namei.c:5193 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5193 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb6afe39b97 RSP: 002b:00007fb6adc30e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fb6adc30ee0 RCX: 00007fb6afe39b97 RDX: 00000000000001ff RSI: 00002000000000c0 RDI: 00000000ffffff9c RBP: 0000200000000200 R08: 0000200000000000 R09: 0000000000000000 R10: 0000200000000200 R11: 0000000000000246 R12: 00002000000000c0 R13: 00007fb6adc30ea0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: #0: ffff88801aa94938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801aa94938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90000117bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000117bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8ed295e0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670 #3: ffff8880626a57b8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x310 drivers/net/wireguard/device.c:249 1 lock held by khungtaskd/38: #0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:12/1180: #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90004fc7bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90004fc7bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 2 locks held by getty/5558: #0: ffff8880270fb0a0 (&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+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5802: #0: ffffffff8d60c0a8 (tasklist_lock){++++}-{3:3}, at: read_lock include/linux/rwlock_rt.h:37 [inline] #0: ffffffff8d60c0a8 (tasklist_lock){++++}-{3:3}, at: __do_wait+0xe1/0x740 kernel/exit.c:1672 4 locks held by kworker/u8:15/5943: #0: ffff88814047b938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88814047b938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc900055d7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900055d7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffff8880399b40d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff88804ec5a8e8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 1 lock held by syz-executor/5990: #0: ffffffff8d60c0a8 (tasklist_lock){++++}-{3:3}, at: read_lock include/linux/rwlock_rt.h:37 [inline] #0: ffffffff8d60c0a8 (tasklist_lock){++++}-{3:3}, at: __do_wait+0xe1/0x740 kernel/exit.c:1672 4 locks held by syz.0.300/8022: 2 locks held by syz.0.300/8045: #0: ffff8880399b4480 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88804ec5acb8 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff88804ec5acb8 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2873 [inline] #1: ffff88804ec5acb8 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2884 [inline] #1: ffff88804ec5acb8 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4888 2 locks held by syz.0.300/8048: #0: ffff8880399b4480 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88804ec5acb8 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff88804ec5acb8 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: open_last_lookups fs/namei.c:4546 [inline] #1: ffff88804ec5acb8 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: path_openat+0xb65/0x3e70 fs/namei.c:4793 2 locks held by syz.0.300/8049: #0: ffff8880399b4480 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88804ec5acb8 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff88804ec5acb8 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2873 [inline] #1: ffff88804ec5acb8 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2884 [inline] #1: ffff88804ec5acb8 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4888 2 locks held by syz-executor/8985: 1 lock held by syz-executor/9245: 2 locks held by syz.2.520/9481: 1 lock held by syz.5.521/9484: #0: ffffffff8d60c0a8 (tasklist_lock){++++}-{3:3}, at: read_lock include/linux/rwlock_rt.h:37 [inline] #0: ffffffff8d60c0a8 (tasklist_lock){++++}-{3:3}, at: mm_update_next_owner+0xdc/0x870 kernel/exit.c:507 1 lock held by syz.5.521/9485: #0: ffffffff8d60c0a8 (tasklist_lock){++++}-{3:3}, at: write_lock_irq include/linux/rwlock_rt.h:104 [inline] #0: ffffffff8d60c0a8 (tasklist_lock){++++}-{3:3}, at: exit_notify kernel/exit.c:742 [inline] #0: ffffffff8d60c0a8 (tasklist_lock){++++}-{3:3}, at: do_exit+0x729/0x2320 kernel/exit.c:983 7 locks held by dhcpcd-run-hook/9507: ============================================= 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 01/13/2026 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+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 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: 9481 Comm: syz.2.520 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline] RIP: 0010:deref_stack_regs arch/x86/kernel/unwind_orc.c:434 [inline] RIP: 0010:unwind_next_frame+0xf00/0x23c0 arch/x86/kernel/unwind_orc.c:611 Code: 16 b7 af 00 48 89 9c 24 80 00 00 00 4d 8b 66 08 49 8d 5e 10 48 89 dd 48 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 80 7c 05 00 00 <74> 08 48 89 df e8 e6 b6 af 00 48 89 5c 24 60 4c 89 7c 24 28 49 8b RSP: 0018:ffffc9000df7f178 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffc9000df7f258 RCX: ffffffff8f383e84 RDX: ffffffff8fab656e RSI: 0000000000000003 RDI: ffffffff8b65e6a0 RBP: 1ffff92001befe4b R08: 0000000000000022 R09: ffffffff8d9c7780 R10: ffffc9000df7f298 R11: ffffffff81ad1370 R12: ffffc9000df78000 R13: ffffc9000df7f250 R14: ffffc9000df7f248 R15: 1ffffffff1f56cae FS: 00007f99431966c0(0000) GS:ffff8881268fc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe391073ec0 CR3: 0000000027bb4000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x124/0x230 mm/page_owner.c:165 __set_page_owner+0x8d/0x4b0 mm/page_owner.c:341 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2486 folio_alloc_mpol_noprof+0x39/0xe0 mm/mempolicy.c:2505 shmem_alloc_folio mm/shmem.c:1890 [inline] shmem_alloc_and_add_folio mm/shmem.c:1932 [inline] shmem_get_folio_gfp+0x644/0x1a80 mm/shmem.c:2556 shmem_get_folio mm/shmem.c:2662 [inline] shmem_write_begin+0x166/0x320 mm/shmem.c:3315 generic_perform_write+0x2af/0x8b0 mm/filemap.c:4314 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3490 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x629/0xba0 fs/read_write.c:686 ksys_write+0x156/0x270 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9944efb58e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007f9943195da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f99431966c0 RCX: 00007f9944efb58e RDX: 0000000001000000 RSI: 00007f993ad76000 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 00007f9943195ee0 R14: 00007f9943195ea0 R15: 00007f993ad76000