INFO: task syz.1.170:8358 blocked for more than 143 seconds. Tainted: G W 6.16.0-syzkaller-11852-g479058002c32 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.170 state:D stack:26024 pid:8358 tgid:8358 ppid:6003 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153 kthread_flush_worker+0x1c6/0x240 kernel/kthread.c:1563 __alloc_workqueue+0x146b/0x1b70 kernel/workqueue.c:5763 alloc_workqueue_noprof+0xd4/0x210 kernel/workqueue.c:5786 btrfs_init_workqueues+0x42c/0x6c0 fs/btrfs/disk-io.c:2000 open_ctree+0x11ef/0x3a10 fs/btrfs/disk-io.c:3424 btrfs_fill_super fs/btrfs/super.c:977 [inline] btrfs_get_tree_super fs/btrfs/super.c:1937 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2074 [inline] btrfs_get_tree+0xf55/0x1820 fs/btrfs/super.c:2108 vfs_get_tree+0x92/0x2b0 fs/super.c:1815 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805 do_mount fs/namespace.c:4133 [inline] __do_sys_mount fs/namespace.c:4344 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4321 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb27169038a RSP: 002b:00007ffefe6fdaf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ffefe6fdb80 RCX: 00007fb27169038a RDX: 00002000000055c0 RSI: 0000200000000200 RDI: 00007ffefe6fdb40 RBP: 00002000000055c0 R08: 00007ffefe6fdb80 R09: 000000000300000a R10: 000000000300000a R11: 0000000000000246 R12: 0000200000000200 R13: 00007ffefe6fdb40 R14: 00000000000055a3 R15: 0000200000000080 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by udevd/5207: #0: ffff8880358bfa18 (&ep->lock){++++}-{3:3}, at: write_lock_irq include/linux/rwlock_rt.h:104 [inline] #0: ffff8880358bfa18 (&ep->lock){++++}-{3:3}, at: ep_poll fs/eventpoll.c:2127 [inline] #0: ffff8880358bfa18 (&ep->lock){++++}-{3:3}, at: do_epoll_wait+0x84d/0xbb0 fs/eventpoll.c:2560 2 locks held by getty/5598: #0: ffff88823bfae8a0 (&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+0x444/0x1410 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:3/5911: 3 locks held by kworker/u8:7/5942: 6 locks held by udevd/6060: 1 lock held by udevd/6069: 1 lock held by udevd/6190: 6 locks held by udevd/6237: #0: ffff88802205eea8 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:884 [inline] #0: ffff88802205eea8 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:848 #1: ffff88803b280250 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:472 [inline] #1: ffff88803b280250 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:277 [inline] #1: ffff88803b280250 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x300 mm/mmap_lock.c:337 #2: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: ___pte_offset_map+0x29/0x200 mm/pgtable-generic.c:286 #3: ffff888026394c58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #3: ffff888026394c58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __pte_offset_map_lock+0x13e/0x210 mm/pgtable-generic.c:401 #4: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #4: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #4: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1bb/0x2c0 kernel/locking/spinlock_rt.c:57 #5: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #5: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x170/0x540 mm/swap.c:-1 2 locks held by kworker/u8:9/6857: 1 lock held by syz.1.170/8358: #0: ffff88802315a0d0 (&type->s_umount_key#53/1){+.+.}-{4:4}, at: alloc_super+0x204/0x990 fs/super.c:345 4 locks held by kworker/u8:11/10100: 1 lock held by syz.3.381/11502: 2 locks held by syz.4.382/11516: #0: ffff88805e1a80d0 (&type->s_umount_key#53/1){+.+.}-{4:4}, at: alloc_super+0x204/0x990 fs/super.c:345 #1: ffffffff8d611078 (bit_wait_table + i){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #1: ffffffff8d611078 (bit_wait_table + i){+.+.}-{3:3}, at: finish_wait kernel/sched/wait.c:394 [inline] #1: ffffffff8d611078 (bit_wait_table + i){+.+.}-{3:3}, at: __wait_on_bit+0x1ff/0x300 kernel/sched/wait_bit.c:55 3 locks held by syz.0.383/11517: #0: ffff88801aa94488 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline] #0: ffff88801aa94488 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x217/0xaa0 fs/read_write.c:682 #1: ffff888054b3c598 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #1: ffff888054b3c598 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:3518 #2: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #2: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x170/0x540 mm/swap.c:-1 3 locks held by syz.5.384/11518: #0: ffff88801aa94488 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline] #0: ffff88801aa94488 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x217/0xaa0 fs/read_write.c:682 #1: ffff8880254a6e88 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #1: ffff8880254a6e88 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:3518 #2: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #2: ffff8880b8833490 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x170/0x540 mm/swap.c:-1 7 locks held by syz.2.385/11535: 1 lock held by udevadm/11536: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G W 6.16.0-syzkaller-11852-g479058002c32 #0 PREEMPT_{RT,(full)} Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 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] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 5911 Comm: kworker/u8:3 Tainted: G W 6.16.0-syzkaller-11852-g479058002c32 #0 PREEMPT_{RT,(full)} Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:get_timer_this_cpu_base kernel/time/timer.c:939 [inline] RIP: 0010:__mod_timer+0x81c/0xf60 kernel/time/timer.c:1101 Code: 01 00 00 00 48 8b 5c 24 20 41 0f b6 44 2d 00 84 c0 0f 85 72 06 00 00 8b 2b e8 f0 bb 49 09 41 89 c5 89 c3 bf 08 00 00 00 89 c6 0f c1 12 00 41 83 fd 07 44 89 34 24 0f 87 69 06 00 00 e8 4c bc RSP: 0018:ffffc90004fff680 EFLAGS: 00000082 RAX: 0000000000000000 RBX: 0000000000000000 RCX: f9fab87ca5ec6a00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 0000000000200000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff520009ffeac R12: ffff8880b8825a80 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000802 FS: 0000000000000000(0000) GS:ffff8881268cd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f46b6524000 CR3: 000000003afb2000 CR4: 00000000003526f0 Call Trace: queue_delayed_work_on+0x18b/0x280 kernel/workqueue.c:2559 queue_delayed_work include/linux/workqueue.h:684 [inline] batadv_forw_packet_queue+0x239/0x2a0 net/batman-adv/send.c:691 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:842 [inline] batadv_iv_ogm_schedule+0x892/0xf00 net/batman-adv/bat_iv_ogm.c:874 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1714 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245