INFO: task syz.1.209:8743 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.209 state:D stack:26872 pid:8743 tgid:8742 ppid:8531 task_flags:0x400040 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] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 __super_lock fs/super.c:57 [inline] super_lock+0x25c/0x3b0 fs/super.c:121 user_get_super+0xc8/0x120 fs/super.c:998 quotactl_block fs/quota/quota.c:890 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x4da/0x950 fs/quota/quota.c:917 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: 0033:0x7f485465f749 RSP: 002b:00007f48528c6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f48548b5fa0 RCX: 00007f485465f749 RDX: 0000000000000000 RSI: 0000200000000440 RDI: ffffffff80000201 RBP: 00007f48546e3f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f48548b6038 R14: 00007f48548b5fa0 R15: 00007ffcd9c65a98 Showing all locks held in the system: 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/u8:8/1128: #0: ffff88803e67e138 ((wq_completion)loop3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88803e67e138 ((wq_completion)loop3){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90004d07bc0 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90004d07bc0 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff888142349160 (&lo->lo_work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:93 [inline] #2: ffff888142349160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_process_work+0xf8/0x11a0 drivers/block/loop.c:1975 1 lock held by udevd/5166: #0: ffff8880b89442a8 (&s->lock_key#53){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #0: ffff8880b89442a8 (&s->lock_key#53){+.+.}-{3:3}, at: ___slab_alloc+0x12f/0x13e0 mm/slub.c:4521 2 locks held by getty/5559: #0: ffff88814e3b80a0 (&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+0x44f/0x1460 drivers/tty/n_tty.c:2211 4 locks held by syz-executor/5795: 1 lock held by syz-executor/8731: #0: ffff8880b89442a8 (&s->lock_key#53){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #0: ffff8880b89442a8 (&s->lock_key#53){+.+.}-{3:3}, at: ___slab_alloc+0x12f/0x13e0 mm/slub.c:4521 1 lock held by syz.1.209/8743: #0: ffff88803d2cc0d0 (&type->s_umount_key#73){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88803d2cc0d0 (&type->s_umount_key#73){++++}-{4:4}, at: super_lock+0x25c/0x3b0 fs/super.c:121 5 locks held by udevd/8861: 6 locks held by kworker/u8:14/8910: #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: ffffc90005117bc0 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90005117bc0 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff88803145c300 (&devlink->lock_key#37){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xbc0 drivers/net/netdevsim/dev.c:908 #3: ffff88802f487520 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #3: ffff88802f487520 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:861 [inline] #3: ffff88802f487520 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x1ad/0xbc0 drivers/net/netdevsim/dev.c:921 #4: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #4: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #4: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1c1/0x3e0 kernel/locking/spinlock_rt.c:57 #5: ffff88813ff25d58 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #5: ffff88813ff25d58 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node+0x44/0x3e0 mm/slub.c:3514 1 lock held by syz.6.221/9025: #0: ffff88803d2cc0d0 (&type->s_umount_key#73){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803d2cc0d0 (&type->s_umount_key#73){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.6.221/9026: #0: ffff88803d2cc0d0 (&type->s_umount_key#73){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803d2cc0d0 (&type->s_umount_key#73){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.6.221/9028: #0: ffff88803d2cc0d0 (&type->s_umount_key#73){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803d2cc0d0 (&type->s_umount_key#73){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 2 locks held by udevd/9449: #0: ffffffff8dc717f8 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:185 [inline] #0: ffffffff8dc717f8 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:277 [inline] #0: ffffffff8dc717f8 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1110 [inline] #0: ffffffff8dc717f8 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_path_number_perm+0x1bc/0x5a0 security/tomoyo/file.c:722 #1: ffff88813ff25d58 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #1: ffff88813ff25d58 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node+0x44/0x3e0 mm/slub.c:3514 6 locks held by kworker/u8:24/9503: 7 locks held by syz.3.380/10532: #0: ffff888032ada480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88805dda1938 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff88805dda1938 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2873 [inline] #1: ffff88805dda1938 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2884 [inline] #1: ffff88805dda1938 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x1fb/0x360 fs/namei.c:4888 #2: ffff88805dda1568 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_mkdir+0x1fb/0xa70 fs/jfs/namei.c:233 #3: ffff88805dd51568 (&jfs_ip->commit_mutex/1){+.+.}-{4:4}, at: jfs_mkdir+0x216/0xa70 fs/jfs/namei.c:234 #4: ffff88805dd515f0 (&jfs_ip->xattr_sem){++++}-{4:4}, at: __jfs_setxattr+0xe1/0x1120 fs/jfs/xattr.c:678 #5: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #5: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #5: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: blk_mq_dispatch_queue_requests+0x552/0x800 block/blk-mq.c:2898 #6: ffff888142349160 (&lo->lo_work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:93 [inline] #6: ffff888142349160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_queue_work drivers/block/loop.c:804 [inline] #6: ffff888142349160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_queue_rq+0x23c/0xb00 drivers/block/loop.c:1911 2 locks held by udevd/10533: #0: ffff888021c688a8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline] #0: ffff888021c688a8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:855 #1: ffff8880b8833cd0 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #1: ffff8880b8833cd0 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x284/0xa90 mm/swap.c:-1 4 locks held by syz.4.379/10540: 2 locks held by syz.9.386/10564: 2 locks held by syz.2.387/10566: #0: ffffffff8dc717f8 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:185 [inline] #0: ffffffff8dc717f8 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:277 [inline] #0: ffffffff8dc717f8 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1110 [inline] #0: ffffffff8dc717f8 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_check_open_permission+0x16a/0x3b0 security/tomoyo/file.c:767 #1: ffff88813ff25d58 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #1: ffff88813ff25d58 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node+0x44/0x3e0 mm/slub.c:3514 ============================================= 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: 29 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] RIP: 0010:lock_acquire+0x11c/0x340 kernel/locking/lockdep.c:5870 Code: 89 e1 45 89 f0 6a 00 6a 00 6a 00 55 ff 74 24 30 e8 d9 02 00 00 48 83 c4 28 48 c7 c7 e2 f9 fd 8c e8 c9 5d 35 09 b8 ff ff ff ff <65> 0f c1 05 9c e7 16 10 83 f8 01 0f 85 ae 00 00 00 9c 58 a9 00 02 RSP: 0000:ffffc90000a3f1b8 EFLAGS: 00000046 RAX: 00000000ffffffff RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000710449ce RSI: ffffffff8cfdf9e2 RDI: ffffffff8b3f5a60 RBP: ffffffff8173dd35 R08: ffffffff8173dd35 R09: ffffffff8d5ae940 R10: ffffc90000a3f378 R11: ffffffff81ab98f0 R12: 0000000000000002 R13: ffffffff8d5ae940 R14: 0000000000000000 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff888126dee000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8b61f4d000 CR3: 0000000027fb8000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_node_noprof+0x23c/0x6f0 mm/slub.c:5315 kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:586 __alloc_skb+0x204/0x3a0 net/core/skbuff.c:690 __netdev_alloc_skb+0xc0/0x500 net/core/skbuff.c:754 netdev_alloc_skb include/linux/skbuff.h:3484 [inline] dev_alloc_skb include/linux/skbuff.h:3497 [inline] __ieee80211_beacon_get+0xc4e/0x1850 net/mac80211/tx.c:5656 ieee80211_beacon_get_tim+0xb4/0x2b0 net/mac80211/tx.c:5778 ieee80211_beacon_get include/net/mac80211.h:5669 [inline] mac80211_hwsim_beacon_tx+0x3c5/0x870 drivers/net/wireless/virtual/mac80211_hwsim.c:2361 __iterate_interfaces+0x2ab/0x590 net/mac80211/util.c:761 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:797 mac80211_hwsim_beacon+0xbb/0x180 drivers/net/wireless/virtual/mac80211_hwsim.c:2395 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x542/0xd00 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x1a3/0x2e0 kernel/time/hrtimer.c:1858 handle_softirqs+0x1df/0x650 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1138 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 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