INFO: task syz.1.2187:12289 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.2187 state:D stack:26232 pid:12289 tgid:12279 ppid:5874 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 io_schedule+0x80/0xd0 kernel/sched/core.c:7906 TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline] txBegin+0x26e/0xb10 fs/jfs/jfs_txnmgr.c:374 jfs_mkdir+0x1e5/0xa70 fs/jfs/namei.c:231 vfs_mkdir+0x306/0x510 fs/namei.c:4374 do_mkdirat+0x247/0x590 fs/namei.c:4407 __do_sys_mkdirat fs/namei.c:4424 [inline] __se_sys_mkdirat fs/namei.c:4422 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4422 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ec3d8d417 RSP: 002b:00007f8ec4c6ce68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f8ec4c6cef0 RCX: 00007f8ec3d8d417 RDX: 00000000000001ff RSI: 0000200000000240 RDI: 00000000ffffff9c RBP: 0000200000000200 R08: 00002000000000c0 R09: 0000000000000000 R10: 0000200000000200 R11: 0000000000000246 R12: 0000200000000240 R13: 00007f8ec4c6ceb0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff8880342c9948 ((wq_completion)udp_tunnel_nic){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8880342c9948 ((wq_completion)udp_tunnel_nic){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000117ba0 ((work_completion)(&utn->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000117ba0 ((work_completion)(&utn->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f73e748 (rtnl_mutex){+.+.}-{4:4}, at: udp_tunnel_nic_device_sync_work+0x29/0xa50 net/ipv4/udp_tunnel_nic.c:736 3 locks held by kworker/u8:1/13: #0: ffff8880300e5148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8880300e5148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000127ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000127ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f73e748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f73e748 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194 1 lock held by khungtaskd/31: #0: ffffffff8e33c560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33c560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e33c560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by kworker/u8:6/1018: #0: ffff8880b8739f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636 2 locks held by getty/5623: #0: ffff88814cb870a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:8/6180: #0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000b067ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000b067ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f73e748 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by kworker/u8:10/7043: #0: ffff8881456b3148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8881456b3148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90003ddfba0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90003ddfba0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 2 locks held by syz.1.2187/12289: #0: ffff888079e68420 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:574 #1: ffff8880594f57e0 (&type->i_mutex_dir_key#16/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1025 [inline] #1: ffff8880594f57e0 (&type->i_mutex_dir_key#16/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0 fs/namei.c:4147 3 locks held by syz-executor/15065: #0: ffffffff8f73e748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f73e748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f73e748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 #1: ffff888033f454e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_open+0x227/0x420 drivers/net/wireguard/device.c:50 #2: ffffffff8e341ff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8e341ff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 2 locks held by syz.5.3255/15297: #0: ffff88807b98c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: do_remount fs/namespace.c:3351 [inline] #0: ffff88807b98c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: path_mount+0xcd4/0xfe0 fs/namespace.c:4104 #1: ffff8880291a2b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_write fs/ext4/ext4.h:1806 [inline] #1: ffff8880291a2b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: __ext4_remount fs/ext4/super.c:6526 [inline] #1: ffff8880291a2b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_reconfigure+0xa85/0x2cc0 fs/ext4/super.c:6799 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 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:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 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: 60 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:__local_bh_enable_ip+0xf7/0x1c0 kernel/softirq.c:402 Code: 00 4c 89 e7 65 8b 05 b8 15 3e 11 25 00 ff 00 00 3d 00 02 00 00 75 05 e8 27 5f 18 00 b8 01 00 00 00 29 d8 65 01 05 99 15 3e 11 <65> 8b 05 92 15 3e 11 a9 00 ff ff 00 75 19 48 c7 c7 60 a5 a9 8b e8 RSP: 0018:ffffc9000211f8c0 EFLAGS: 00000083 RAX: 00000000fffffe00 RBX: 0000000000000201 RCX: ae7d51cb5fbcfc00 RDX: 0000000000000000 RSI: ffffffff8ddac14f RDI: ffffffff8c036200 RBP: ffffc9000211f958 R08: ffffffff8fc3ce37 R09: 1ffffffff1f879c6 R10: dffffc0000000000 R11: fffffbfff1f879c7 R12: ffffffff8b5063a8 R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff92000423f18 FS: 0000000000000000(0000) GS:ffff8881259f0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555573339608 CR3: 000000007798e000 CR4: 00000000003526f0 Call Trace: spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_nc_purge_paths+0x318/0x3b0 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x369/0x610 net/batman-adv/network-coding.c:722 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245