INFO: task udevd:5846 blocked for more than 143 seconds. Not tainted 6.15.0-rc2-syzkaller-00471-g119009db2674 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23512 pid:5846 tgid:5846 ppid:5202 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746 bdev_open+0xf7/0xcd0 block/bdev.c:907 blkdev_open+0x38e/0x4e0 block/fops.c:652 do_dentry_open+0xdec/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3880 [inline] path_openat+0x2caf/0x35d0 fs/namei.c:4039 do_filp_open+0x284/0x4e0 fs/namei.c:4066 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x249/0x2a0 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc5ff7169a4 RSP: 002b:00007ffc6e4b2f70 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc5ff7169a4 RDX: 0000000000080000 RSI: 000055b8bd28da40 RDI: 00000000ffffff9c RBP: 000055b8bd28da40 R08: 000055b8bd2822c0 R09: 00007fc5ff7f1c10 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000 R13: 000055b8bd2822c0 R14: 0000000000000000 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by kdevtmpfs/26: #0: ffff88801c2e0950 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #0: ffff88801c2e0950 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: __kern_path_locked+0x1ca/0x430 fs/namei.c:2765 1 lock held by khungtaskd/31: #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764 3 locks held by kworker/u8:2/36: #0: ffff88814d40b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88814d40b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000ad7c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000ad7c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x110/0x16a0 net/ipv6/addrconf.c:4195 3 locks held by kworker/u8:3/53: #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000be7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000be7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 5 locks held by kworker/u8:7/2967: #0: ffff88801bef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801bef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000b7d7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000b7d7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900de750 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17c/0xd60 net/core/net_namespace.c:608 #3: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xde/0x880 net/core/dev.c:12524 #4: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #4: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x384/0x830 kernel/rcu/tree_exp.h:998 2 locks held by kworker/u8:8/2985: #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000b9f7c60 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000b9f7c60 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 1 lock held by udevd/5202: #0: ffff888143356358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf7/0xcd0 block/bdev.c:907 2 locks held by getty/5592: #0: ffff88803189e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036e32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222 1 lock held by udevd/5846: #0: ffff8880254c6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf7/0xcd0 block/bdev.c:907 1 lock held by syz.1.17/6075: #0: ffff8880254c6358 (&disk->open_mutex){+.+.}-{4:4}, at: loop_reread_partitions drivers/block/loop.c:435 [inline] #0: ffff8880254c6358 (&disk->open_mutex){+.+.}-{4:4}, at: loop_set_status+0x7be/0xb20 drivers/block/loop.c:1243 1 lock held by syz.5.21/6507: #0: ffff888143356358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x17e/0x700 block/bdev.c:1090 1 lock held by syz-executor/7129: #0: ffff8880254c6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf7/0xcd0 block/bdev.c:907 1 lock held by syz-executor/7173: #0: ffff888143350358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x17e/0x700 block/bdev.c:1090 1 lock held by syz-executor/7195: #0: ffff888143352358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x17e/0x700 block/bdev.c:1090 1 lock held by syz-executor/7330: #0: ffff888143356358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf7/0xcd0 block/bdev.c:907 1 lock held by syz-executor/7999: #0: ffff888143366358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x17e/0x700 block/bdev.c:1090 1 lock held by syz-executor/8148: #0: ffff8880254c6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf7/0xcd0 block/bdev.c:907 1 lock held by syz-executor/8358: #0: ffff888143350358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf7/0xcd0 block/bdev.c:907 1 lock held by syz-executor/8620: #0: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x831/0x11b0 net/ipv6/addrconf.c:5028 1 lock held by syz.0.36/8685: #0: ffff8880254c4358 (&disk->open_mutex){+.+.}-{4:4}, at: loop_reread_partitions drivers/block/loop.c:435 [inline] #0: ffff8880254c4358 (&disk->open_mutex){+.+.}-{4:4}, at: loop_set_status+0x7be/0xb20 drivers/block/loop.c:1243 2 locks held by syz-executor/8944: #0: ffffffff9060bc38 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff9060bc38 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff9060bc38 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:570 #1: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xd68/0x1fe0 net/core/rtnetlink.c:4064 2 locks held by syz-executor/8961: #0: ffffffff900de750 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:514 #1: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #1: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11123 1 lock held by syz-executor/9091: #0: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900eb288 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by modprobe/9199: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc2-syzkaller-00471-g119009db2674 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:437 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 13 Comm: kworker/u8:1 Not tainted 6.15.0-rc2-syzkaller-00471-g119009db2674 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:-1 [inline] RIP: 0010:lock_release+0x204/0x3e0 kernel/locking/lockdep.c:5889 Code: c3 7f d3 4c 89 ef 4c 89 fe 48 8b 54 24 18 e8 d3 3b 00 00 48 8d 1d ac 96 c6 11 4c 8b 34 24 48 c7 c7 f1 7f 4c 8e e8 7c 56 89 0a ff ff ff ff 65 0f c1 05 af d2 c6 11 83 f8 01 0f 85 bf 00 00 00 RSP: 0000:ffffc900001273a0 EFLAGS: 00000082 RAX: 0000000000000001 RBX: ffffffff93651020 RCX: 0000000000000004 RDX: 0000000000000000 RSI: ffffffff8e4c7ff1 RDI: ffffffff8ca0e180 RBP: ffff88801c680b90 R08: ffffc9000012753f R09: 0000000000000000 R10: ffffc90000127530 R11: fffff52000024ea8 R12: 0000000000000004 R13: ffff88801c680000 R14: 0000000000000206 R15: ffffffff8ed3df20 FS: 0000000000000000(0000) GS:ffff8881250cf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6fb6a38440 CR3: 000000000eb38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x1a9f/0x23b0 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/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+0x9d/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4341 [inline] __kmalloc_node_track_caller_noprof+0x295/0x4d0 mm/slub.c:4360 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:599 __alloc_skb+0x1f2/0x480 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1340 [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+0x260/0xb50 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245