INFO: task udevd:6329 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24640 pid:6329 tgid:6329 ppid:5160 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0x164/0x360 kernel/sched/core.c:7005 io_schedule+0x80/0xe0 kernel/sched/core.c:7832 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250 __wait_on_bit_lock+0xe3/0x4b0 kernel/sched/wait_bit.c:93 out_of_line_wait_on_bit_lock+0x13b/0x190 kernel/sched/wait_bit.c:120 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline] __lock_buffer fs/buffer.c:72 [inline] lock_buffer include/linux/buffer_head.h:432 [inline] block_read_full_folio+0x38f/0x830 fs/buffer.c:2436 filemap_read_folio+0x137/0x3b0 mm/filemap.c:2501 filemap_update_page mm/filemap.c:2588 [inline] filemap_get_pages+0x16de/0x1ea0 mm/filemap.c:2718 filemap_read+0x44a/0x1240 mm/filemap.c:2805 blkdev_read_iter+0x311/0x440 block/fops.c:855 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x58b/0xa80 fs/read_write.c:574 ksys_read+0x156/0x270 fs/read_write.c:717 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: 0033:0x7f7cd37c4407 RSP: 002b:00007fffc5499960 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f7cd36d6880 RCX: 00007f7cd37c4407 RDX: 0000000000000200 RSI: 00007f7cd2d89000 RDI: 0000000000000009 RBP: 000055603a695050 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000018 R13: 0000000000001000 R14: 000055603a6aa6f8 R15: 00007f7cd3f1a39c INFO: task syz.1.382:8092 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.382 state:D stack:25664 pid:8092 tgid:8091 ppid:6320 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0x164/0x360 kernel/sched/core.c:7005 io_schedule+0x80/0xe0 kernel/sched/core.c:7832 folio_wait_bit_common+0x6dd/0xbc0 mm/filemap.c:1323 folio_lock include/linux/pagemap.h:1170 [inline] __find_get_block_slow fs/buffer.c:206 [inline] find_get_block_common+0x34f/0xe10 fs/buffer.c:1405 bdev_getblk+0x53/0x6e0 include/linux/gfp.h:-1 __getblk include/linux/buffer_head.h:380 [inline] sb_getblk include/linux/buffer_head.h:386 [inline] __ext4_get_inode_loc+0x7d8/0xfa0 fs/ext4/inode.c:4812 ext4_get_inode_loc fs/ext4/inode.c:4915 [inline] ext4_reserve_inode_write+0x18b/0x360 fs/ext4/inode.c:6235 ext4_xattr_set_handle+0x537/0x14c0 fs/ext4/xattr.c:2397 ext4_initxattrs+0x9f/0x110 fs/ext4/xattr_security.c:44 security_inode_init_security+0x296/0x3d0 security/security.c:1344 __ext4_new_inode+0x332f/0x3d20 fs/ext4/ialloc.c:1324 ext4_mkdir+0x3da/0xbf0 fs/ext4/namei.c:3005 vfs_mkdir+0x40b/0x630 fs/namei.c:5233 filename_mkdirat+0x289/0x520 fs/namei.c:5266 __do_sys_mkdir fs/namei.c:5293 [inline] __se_sys_mkdir+0x34/0x150 fs/namei.c:5290 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: 0033:0x7faac3ebc799 RSP: 002b:00007faac3516028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007faac4135fa0 RCX: 00007faac3ebc799 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000680 RBP: 00007faac3f52bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faac4136038 R14: 00007faac4135fa0 R15: 00007fffa69721b8 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff88801eab1138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801eab1138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffff88801b2840d0 (&type->s_umount_key#43){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 1 lock held by khungtaskd/38: #0: ffffffff8ddcb880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:3/56: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc9000122fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000122fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 2 locks held by kworker/u8:4/68: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc9000153fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000153fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 1 lock held by udevd/5160: 2 locks held by getty/5552: #0: ffff8880384ef0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/6225: 1 lock held by syz-executor/6319: 2 locks held by udevd/6329: #0: ffff8880226a88a8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff8880226a88a8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:854 #1: ffff8880226a8a78 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline] #1: ffff8880226a8a78 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2554 [inline] #1: ffff8880226a8a78 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x931/0x1ea0 mm/filemap.c:2718 1 lock held by syz-executor/6330: 1 lock held by syz-executor/6331: 1 lock held by udevd/6332: 3 locks held by kworker/0:7/6694: 3 locks held by syz.1.382/8092: #0: ffff888021b80480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff8880446a1c70 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff8880446a1c70 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff8880446a1c70 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff8880446a1c70 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922 #2: ffff88804d781878 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] #2: ffff88804d781878 (&ei->xattr_sem){++++}-{4:4}, at: ext4_xattr_set_handle+0x19c/0x14c0 fs/ext4/xattr.c:2372 1 lock held by udevd/8698: 2 locks held by udevd/8707: 1 lock held by syz.2.2098/14045: #0: ffff88802c04e0d0 (&type->s_umount_key#29/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 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: 6694 Comm: kworker/0:7 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 Workqueue: events_power_efficient wg_ratelimiter_gc_entries RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] RIP: 0010:lock_release+0x259/0x3d0 kernel/locking/lockdep.c:5891 Code: 41 8d 45 ff 41 89 c5 7f d0 4c 89 ff 4c 89 f6 48 8b 54 24 18 e8 38 2f 00 00 48 8b 5c 24 08 48 c7 c7 df bb 7b 8d e8 07 57 82 09 ff ff ff ff 65 0f c1 05 da 0f ae 10 83 f8 01 75 2e 9c 58 a9 00 RSP: 0018:ffffc90003cb7a08 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000287 RCX: 0000000000000046 RDX: 00000000374003d5 RSI: ffffffff8d7bbbdf RDI: ffffffff8ba65f80 RBP: ffff8880274bc908 R08: ffffffff8b24d1d0 R09: ffffffff8ddcb880 R10: 0000000000000000 R11: fffffbfff1ed4697 R12: 0000000000000003 R13: 0000000000000003 R14: ffffffff8e88c078 R15: ffff8880274bbd00 FS: 0000000000000000(0000) GS:ffff88812633f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9544a6da08 CR3: 0000000028836000 CR4: 00000000003526f0 Call Trace: rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80 spin_unlock include/linux/spinlock_rt.h:109 [inline] wg_ratelimiter_gc_entries+0x3a8/0x480 drivers/net/wireguard/ratelimiter.c:76 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 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