INFO: task udevd:6255 blocked for more than 143 seconds. Not tainted 6.16.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23568 pid:6255 tgid:6255 ppid:5188 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 wait_for_reconnect drivers/block/nbd.c:1104 [inline] nbd_handle_cmd drivers/block/nbd.c:1146 [inline] nbd_queue_rq+0xd12/0x12d0 drivers/block/nbd.c:1204 blk_mq_dispatch_rq_list+0x413/0x1e20 block/blk-mq.c:2118 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xcb7/0x15f0 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x239/0x670 block/blk-mq.c:2356 blk_mq_dispatch_list+0x514/0x1310 block/blk-mq.c:2917 blk_mq_flush_plug_list block/blk-mq.c:2965 [inline] blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2937 __blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1220 blk_finish_plug block/blk-core.c:1247 [inline] blk_finish_plug block/blk-core.c:1244 [inline] __submit_bio+0x545/0x690 block/blk-core.c:649 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x660/0xd30 block/blk-core.c:751 submit_bio_noacct+0x50d/0x1eb0 block/blk-core.c:874 submit_bh fs/buffer.c:2836 [inline] block_read_full_folio+0x34e/0x850 fs/buffer.c:2454 filemap_read_folio+0xc8/0x2a0 mm/filemap.c:2412 do_read_cache_folio+0x263/0x5c0 mm/filemap.c:3894 read_mapping_folio include/linux/pagemap.h:972 [inline] read_part_sector+0xd4/0x370 block/partitions/core.c:722 adfspart_check_ICS+0x93/0x940 block/partitions/acorn.c:360 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x723/0x1520 block/partitions/core.c:693 blkdev_get_whole+0x187/0x290 block/bdev.c:748 bdev_open+0x2c7/0xe40 block/bdev.c:957 blkdev_open+0x280/0x3f0 block/fops.c:676 do_dentry_open+0x744/0x1c10 fs/open.c:964 vfs_open+0x82/0x3f0 fs/open.c:1094 do_open fs/namei.c:3896 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4055 do_filp_open+0x20b/0x470 fs/namei.c:4082 do_sys_openat2+0x11b/0x1d0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc9ea4a7407 RSP: 002b:00007fff510a6dd0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fc9eac19880 RCX: 00007fc9ea4a7407 RDX: 00000000000a0800 RSI: 000055c401a239e0 RDI: ffffffffffffff9c RBP: 000055c4017e12c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055c401a2c4a0 R13: 000055c401a268f0 R14: 0000000000000000 R15: 000055c401a2c4a0 INFO: task kworker/1:2H:10776 blocked for more than 144 seconds. Not tainted 6.16.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:2H state:D stack:27344 pid:10776 tgid:10776 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: kblockd blk_mq_requeue_work Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 wait_for_reconnect drivers/block/nbd.c:1104 [inline] nbd_handle_cmd drivers/block/nbd.c:1146 [inline] nbd_queue_rq+0xd12/0x12d0 drivers/block/nbd.c:1204 blk_mq_dispatch_rq_list+0x413/0x1e20 block/blk-mq.c:2118 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xcb7/0x15f0 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x239/0x670 block/blk-mq.c:2356 blk_mq_run_hw_queues+0x117/0x450 block/blk-mq.c:2405 blk_mq_requeue_work+0x59f/0x7d0 block/blk-mq.c:1572 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c4940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 3 locks held by kworker/u8:8/3444: #0: ffff888031ad3148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000c567d10 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9034c628 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff9034c628 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x120/0x14e0 net/ipv6/addrconf.c:4198 2 locks held by getty/5576: #0: ffff8880328d50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by udevd/6255: #0: ffff888143755358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 #1: ffff888142f5eb10 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #1: ffff888142f5eb10 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #1: ffff888142f5eb10 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x22b/0x670 block/blk-mq.c:2356 #2: ffff8880266f7338 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xbd/0x12d0 drivers/block/nbd.c:1196 3 locks held by kworker/0:14/8392: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9001ca17d10 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888022f17240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1bb/0x2e80 drivers/net/netdevsim/fib.c:1490 4 locks held by kworker/1:2H/10776: #0: ffff88801d282548 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900048a7d10 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888142f5eb10 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #2: ffff888142f5eb10 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #2: ffff888142f5eb10 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x22b/0x670 block/blk-mq.c:2356 #3: ffff8880266f7178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xbd/0x12d0 drivers/block/nbd.c:1196 3 locks held by syz-executor/13860: #0: ffffffff9034c628 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff9034c628 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff9034c628 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4054 #1: ffff88805299d4e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_open+0x203/0x4e0 drivers/net/wireguard/device.c:50 #2: ffffffff8e5cff38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:304 1 lock held by syz.7.1977/14018: #0: ffffffff8e5cfe00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3786 3 locks held by syz.7.1977/14019: #0: ffff88807c854428 (sb_writers#18){.+.+}-{0:0}, at: open_last_lookups fs/namei.c:3805 [inline] #0: ffff88807c854428 (sb_writers#18){.+.+}-{0:0}, at: path_openat+0x1f0f/0x2cb0 fs/namei.c:4052 #1: ffff8880591db948 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #1: ffff8880591db948 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: open_last_lookups fs/namei.c:3813 [inline] #1: ffff8880591db948 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: path_openat+0x1534/0x2cb0 fs/namei.c:4052 #2: ffff8880591dbe08 (&fi->mutex){+.+.}-{4:4}, at: fuse_lock_inode+0xd2/0x110 fs/fuse/inode.c:594 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 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: 3444 Comm: kworker/u8:8 Not tainted 6.16.0-rc4-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:416 Code: 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d e9 46 c7 27 06 e8 71 00 c7 fc eb a0 e8 fa 00 c7 RSP: 0018:ffffc9000c567518 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: ffffffff855bfb65 RDI: ffffffff9b088320 RBP: ffffffff9b0882e0 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff9b0882e0 R15: ffffffff9b0885a0 FS: 0000000000000000(0000) GS:ffff888124752000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f870db81178 CR3: 000000005dfca000 CR4: 00000000003526f0 DR0: 0000000000000007 DR1: 0000000000004e6a DR2: 0000000000000007 DR3: 00000000000002d5 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: serial_out drivers/tty/serial/8250/8250.h:142 [inline] serial8250_clear_IER+0x9b/0xc0 drivers/tty/serial/8250/8250_port.c:713 serial8250_console_write+0x255/0x1890 drivers/tty/serial/8250/8250_port.c:3421 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x801/0xc60 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xd8/0x210 kernel/printk/printk.c:3325 vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450 _printk+0xc7/0x100 kernel/printk/printk.c:2475 ieee80211_sta_find_ibss net/mac80211/ibss.c:1443 [inline] ieee80211_ibss_work+0xb9e/0x1480 net/mac80211/ibss.c:1662 ieee80211_iface_work+0xcee/0x1020 net/mac80211/iface.c:1744 cfg80211_wiphy_work+0x3dc/0x550 net/wireless/core.c:435 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245