INFO: task syz.9.897:12591 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.897 state:D stack:25344 pid:12591 tgid:12590 ppid:11780 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 io_schedule+0x80/0xe0 kernel/sched/core.c:7835 TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline] txBegin+0x27d/0xc00 fs/jfs/jfs_txnmgr.c:375 jfs_mkdir+0x21d/0xb00 fs/jfs/namei.c:232 vfs_mkdir+0x40b/0x630 fs/namei.c:5239 filename_mkdirat+0x289/0x520 fs/namei.c:5272 __do_sys_mkdir fs/namei.c:5299 [inline] __se_sys_mkdir+0x34/0x150 fs/namei.c:5296 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: 0033:0x7f320dbec819 RSP: 002b:00007f320be46028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007f320de65fa0 RCX: 00007f320dbec819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000300 RBP: 00007f320dc82c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f320de66038 R14: 00007f320de65fa0 R15: 00007ffda71a90d8 Showing all locks held in the system: 1 lock held by khungtaskd/37: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 6 locks held by kworker/u8:4/67: 2 locks held by getty/5553: #0: ffff888037b2d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5820: #0: ffff888066a12a08 (&ep->lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:96 [inline] #0: ffff888066a12a08 (&ep->lock){+.+.}-{3:3}, at: ep_poll fs/eventpoll.c:2040 [inline] #0: ffff888066a12a08 (&ep->lock){+.+.}-{3:3}, at: do_epoll_wait+0x851/0xbd0 fs/eventpoll.c:2462 3 locks held by kworker/u8:23/8921: #0: ffff888032296938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888032296938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90004a5fc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90004a5fc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15d338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f15d338 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4738 3 locks held by kworker/u8:29/8927: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90004c8fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90004c8fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15d338 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 4 locks held by kworker/u8:30/8928: 4 locks held by kworker/u8:39/8937: 6 locks held by kworker/u8:41/8939: #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90004ef7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90004ef7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f14eb80 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffff88802bdfc160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #3: ffff88802bdfc160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff88802bdfc160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x11b/0x3f0 net/devlink/core.c:504 #4: ffff88802a24a300 (&devlink->lock_key#11){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:274 [inline] #4: ffff88802a24a300 (&devlink->lock_key#11){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff88802a24a300 (&devlink->lock_key#11){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x12d/0x3f0 net/devlink/core.c:504 #5: ffffffff8f15d338 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1180 6 locks held by udevd/9525: 3 locks held by syz-executor/12479: #0: ffff88803b4820d0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88803b4820d0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88803b4820d0 (&type->s_umount_key#61){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffff88803b482b08 (&s->s_sync_lock){+.+.}-{4:4}, at: wait_sb_inodes fs/fs-writeback.c:2751 [inline] #1: ffff88803b482b08 (&s->s_sync_lock){+.+.}-{4:4}, at: sync_inodes_sb+0x2cb/0xc30 fs/fs-writeback.c:2945 #2: ffffffff8da1e0b8 (&folio_wait_table[i]){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffffffff8da1e0b8 (&folio_wait_table[i]){+.+.}-{3:3}, at: finish_wait+0xbe/0x1e0 kernel/sched/wait.c:394 2 locks held by syz.9.897/12591: #0: ffff88805eed0480 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888066100f78 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888066100f78 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2929 [inline] #1: ffff888066100f78 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2940 [inline] #1: ffff888066100f78 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4928 6 locks held by syz.6.1098/14271: 7 locks held by udevadm/14258: 2 locks held by syz.8.1100/14285: 3 locks held by sed/14286: 1 lock held by syz-executor/14288: #0: ffffffff8f15d338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f15d338 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8928 Comm: kworker/u8:30 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: bat_events batadv_dat_purge RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline] RIP: 0010:check_preemption_disabled+0x2a/0xe0 lib/smp_processor_id.c:19 Code: 55 41 57 41 56 53 65 8b 05 47 93 2a 07 65 8b 0d 3c 93 2a 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d e9 99 a5 03 00 cc 9c 59 c1 00 02 00 00 74 ea 65 4c 8b 3d ee 92 2a 07 41 f6 47 2f 04 74 RSP: 0018:ffffc90004d2fa08 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000200 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8b4b3b00 RDI: ffffffff8ba67a80 RBP: 1ffff11004d11ce4 R08: ffffffff8f6a74b7 R09: 1ffffffff1ed4e96 R10: dffffc0000000000 R11: fffffbfff1ed4e97 R12: 0000000000000282 R13: dffffc0000000000 R14: ffff88802688e724 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888126432000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c5779b6028 CR3: 00000000293b0000 CR4: 00000000003526f0 Call Trace: __local_bh_enable_ip+0xe3/0x2b0 kernel/softirq.c:283 local_bh_enable include/linux/bottom_half.h:33 [inline] spin_unlock_bh include/linux/spinlock_rt.h:116 [inline] __batadv_dat_purge+0x344/0x400 net/batman-adv/distributed-arp-table.c:185 batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:204 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 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