INFO: task udevd:6573 blocked for more than 144 seconds. Not tainted 6.13.0-rc1-syzkaller-00337-g7503345ac5f5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:21040 pid:6573 tgid:6573 ppid:5193 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 wait_for_reconnect drivers/block/nbd.c:1043 [inline] nbd_handle_cmd drivers/block/nbd.c:1085 [inline] nbd_queue_rq+0x7d9/0x2ef0 drivers/block/nbd.c:1143 blk_mq_dispatch_rq_list+0xad3/0x19d0 block/blk-mq.c:2120 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline] __blk_mq_sched_dispatch_requests+0xb8a/0x1840 block/blk-mq-sched.c:309 blk_mq_sched_dispatch_requests+0xd6/0x190 block/blk-mq-sched.c:331 blk_mq_run_hw_queue+0x354/0x500 block/blk-mq.c:2354 blk_mq_flush_plug_list+0x118e/0x1870 block/blk-mq.c:2915 __blk_flush_plug+0x420/0x500 block/blk-core.c:1213 blk_finish_plug block/blk-core.c:1240 [inline] __submit_bio+0x46a/0x560 block/blk-core.c:637 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:739 submit_bh fs/buffer.c:2819 [inline] block_read_full_folio+0x93b/0xcd0 fs/buffer.c:2446 filemap_read_folio+0x14b/0x630 mm/filemap.c:2366 do_read_cache_folio+0x3f5/0x850 mm/filemap.c:3826 read_mapping_folio include/linux/pagemap.h:1011 [inline] read_part_sector+0xb3/0x330 block/partitions/core.c:722 adfspart_check_ICS+0xd9/0x9a0 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+0x72c/0x13f0 block/partitions/core.c:693 blkdev_get_whole+0x2d2/0x450 block/bdev.c:707 bdev_open+0x2d4/0xc50 block/bdev.c:916 blkdev_open+0x389/0x4f0 block/fops.c:627 do_dentry_open+0xbe1/0x1b70 fs/open.c:945 vfs_open+0x3e/0x330 fs/open.c:1075 do_open fs/namei.c:3828 [inline] path_openat+0x2c84/0x3590 fs/namei.c:3987 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1428 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f70a29169a4 RSP: 002b:00007ffe46bf1310 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055b46c92ff60 RCX: 00007f70a29169a4 RDX: 00000000000a0800 RSI: 000055b46c91c550 RDI: 00000000ffffff9c RBP: 000055b46c91c550 R08: 0000000000000001 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000a0800 R13: 000055b46c93c320 R14: 0000000000000001 R15: 000055b46c91b910 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 2 locks held by kworker/u8:4/71: 2 locks held by kworker/u8:5/1128: 2 locks held by kworker/u8:7/3460: 2 locks held by getty/5574: #0: ffff888030c2e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5819: #0: ffff8880b863e758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:606 3 locks held by udevd/5972: #0: ffff888025b344c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:904 #1: ffff88801e7f2710 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:158 [inline] #1: ffff88801e7f2710 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:249 [inline] #1: ffff88801e7f2710 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x32b/0x500 block/blk-mq.c:2354 #2: ffff888025be51f8 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xfe/0x2ef0 drivers/block/nbd.c:1135 3 locks held by udevd/6573: #0: ffff888025a574c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:904 #1: ffff88801eb6df10 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:158 [inline] #1: ffff88801eb6df10 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:249 [inline] #1: ffff88801eb6df10 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x32b/0x500 block/blk-mq.c:2354 #2: ffff888025b18bb8 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xfe/0x2ef0 drivers/block/nbd.c:1135 3 locks held by udevd/6710: #0: ffff888025b334c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:904 #1: ffff88801e7f2390 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:158 [inline] #1: ffff88801e7f2390 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:249 [inline] #1: ffff88801e7f2390 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x32b/0x500 block/blk-mq.c:2354 #2: ffff888025bb92b8 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xfe/0x2ef0 drivers/block/nbd.c:1135 2 locks held by syz.0.379/7149: #0: ffff88805aed60e0 (&type->s_umount_key#51/1){+.+.}-{4:4}, at: alloc_super+0x221/0x9d0 fs/super.c:344 #1: ffff888025a574c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:904 1 lock held by syz.3.746/8487: #0: ffff888025b344c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:904 1 lock held by syz.2.747/8489: #0: ffff888025b334c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:904 4 locks held by syz-executor/8657: 2 locks held by syz.5.842/8825: 1 lock held by syz.1.843/8838: #0: ffffffff8e93cfb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93cfb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 1 lock held by syz.7.844/8841: 1 lock held by syz.4.848/8862: #0: ffffffff8e93cfb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #0: ffffffff8e93cfb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc1-syzkaller-00337-g7503345ac5f5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline] watchdog+0xff6/0x1040 kernel/hung_task.c:397 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11 Comm: kworker/u8:0 Not tainted 6.13.0-rc1-syzkaller-00337-g7503345ac5f5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:arch_stack_walk+0x76/0x150 arch/x86/kernel/stacktrace.c:18 Code: 00 00 48 c7 45 a8 00 00 00 00 48 c7 45 a0 00 00 00 00 48 c7 45 98 00 00 00 00 48 c7 45 90 00 00 00 00 48 c7 45 88 00 00 00 00 <48> c7 45 80 00 00 00 00 48 c7 85 78 ff ff ff 00 00 00 00 48 c7 85 RSP: 0018:ffffc90000107580 EFLAGS: 00000282 RAX: f94a74171ccbb600 RBX: ffffc90000107670 RCX: 0000000000000000 RDX: ffff88801bef3c00 RSI: ffffc90000107660 RDI: ffffffff818b36a0 RBP: ffffc90000107610 R08: dffffc0000000000 R09: 0000000000000000 R10: ffffc90000107700 R11: ffffffff818b36a0 R12: ffff88801bef3c00 R13: ffffffff818b36a0 R14: ffffc90000107660 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055556ce03808 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4283 [inline] __kmalloc_node_track_caller_noprof+0x28b/0x4c0 mm/slub.c:4302 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678 alloc_skb include/linux/skbuff.h:1323 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x261/0xb50 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244