INFO: task syz.0.346:5651 blocked for more than 143 seconds. Not tainted 5.15.178-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.346 state:D stack:25440 pid: 5651 ppid: 4165 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0xac/0x300 kernel/time/timer.c:1890 do_wait_for_common+0x2d9/0x480 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x48/0x60 kernel/sched/completion.c:138 kthread_stop+0x178/0x580 kernel/kthread.c:666 ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:263 ext4_fill_super+0x6d67/0xa110 fs/ext4/super.c:5089 mount_bdev+0x2c9/0x3f0 fs/super.c:1400 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x2ba/0xb40 fs/namespace.c:3012 do_mount fs/namespace.c:3355 [inline] __do_sys_mount fs/namespace.c:3563 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3540 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f0d9899a90a RSP: 002b:00007f0d96801e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f0d96801ef0 RCX: 00007f0d9899a90a RDX: 0000400000000040 RSI: 0000400000000000 RDI: 00007f0d96801eb0 RBP: 0000400000000040 R08: 00007f0d96801ef0 R09: 0000000003010008 R10: 0000000003010008 R11: 0000000000000246 R12: 0000400000000000 R13: 00007f0d96801eb0 R14: 0000000000000538 R15: 0000400000000340 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: #0: ffff8880175cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90000ce7d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8dc36b10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x166/0xc90 net/core/net_namespace.c:572 #3: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #3: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845 1 lock held by khungtaskd/27: #0: ffffffff8cb1fce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by udevd/3545: #0: ffff88802081bd18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817 1 lock held by dhcpcd/3837: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x12e/0x6d0 net/netlink/af_netlink.c:2334 2 locks held by getty/3922: #0: ffff88814c724098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 3 locks held by kworker/1:4/4211: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000307fd20 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff888077b5e240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2cd/0x4120 drivers/net/netdevsim/fib.c:1480 2 locks held by kworker/1:15/4472: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000381fd20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 1 lock held by syz.0.346/5651: #0: ffff88807dc1e0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229 1 lock held by syz.7.738/7834: #0: ffff88807dc1e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:716 2 locks held by syz-executor/7861: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5644 #1: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845 1 lock held by syz.2.747/7925: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5644 2 locks held by syz.6.748/7952: #0: ffff88802081bd18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912 #1: ffff88814788e468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2070 1 lock held by dhcpcd/7970: #0: ffff88807a96a120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1684 [inline] #0: ffff88807a96a120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd50 net/packet/af_packet.c:3213 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4207 Comm: kworker/u4:4 Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: loop6 loop_rootcg_workfn RIP: 0010:__bfs kernel/locking/lockdep.c:1698 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1805 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2745 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3057 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3172 [inline] RIP: 0010:validate_chain+0x1a38/0x5930 kernel/locking/lockdep.c:3788 Code: 3a 11 4d 85 e4 0f 84 f9 04 00 00 4d 8d 74 24 10 4c 89 f1 48 c1 e9 03 48 b8 00 00 00 00 00 fc ff df 48 89 4c 24 50 80 3c 01 00 <74> 08 4c 89 f7 e8 1e cb 66 00 49 8b 1e 48 85 db 0f 84 99 26 00 00 RSP: 0018:ffffc9000302f020 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 1ffff92000605e28 RCX: 1ffffffff267670f RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffc9000302f140 RBP: ffffc9000302f2d0 R08: dffffc0000000000 R09: fffffbfff2131821 R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff933b3868 R13: ffff8880626bc730 R14: ffffffff933b3878 R15: ffffffff933b3868 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007711e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 do_write_seqcount_begin_nested include/linux/seqlock.h:519 [inline] do_write_seqcount_begin include/linux/seqlock.h:545 [inline] psi_group_change+0x11b/0x1180 kernel/sched/psi.c:710 psi_enqueue kernel/sched/stats.h:104 [inline] enqueue_task+0x2fe/0x3a0 kernel/sched/core.c:1970 activate_task kernel/sched/core.c:2002 [inline] ttwu_do_activate+0x1cf/0x430 kernel/sched/core.c:3611 ttwu_queue kernel/sched/core.c:3820 [inline] try_to_wake_up+0x795/0x1300 kernel/sched/core.c:4143 wakeup_softirqd kernel/softirq.c:80 [inline] raise_softirq_irqoff kernel/softirq.c:688 [inline] raise_softirq+0xf1/0x1a0 kernel/softirq.c:696 blk_mq_raise_softirq block/blk-mq.c:652 [inline] blk_mq_complete_request_remote+0x1a5/0x640 block/blk-mq.c:673 blk_mq_complete_request+0x15/0xa0 block/blk-mq.c:689 loop_handle_cmd drivers/block/loop.c:2251 [inline] loop_process_work+0x19f1/0x2af0 drivers/block/loop.c:2274 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287