INFO: task syz.4.20:5111 blocked for more than 143 seconds. Not tainted 6.1.138-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.20 state:D stack:28968 pid:5111 ppid:5003 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522 inode_lock_shared include/linux/fs.h:768 [inline] lookup_slow+0x46/0x70 fs/namei.c:1706 walk_component+0x2be/0x3f0 fs/namei.c:1998 lookup_last fs/namei.c:2455 [inline] path_lookupat+0x169/0x440 fs/namei.c:2479 filename_lookup+0x1f0/0x500 fs/namei.c:2508 user_path_at_empty+0x3e/0x60 fs/namei.c:2905 user_path_at include/linux/namei.h:57 [inline] do_mount fs/namespace.c:3397 [inline] __do_sys_mount fs/namespace.c:3608 [inline] __se_sys_mount+0x297/0x3c0 fs/namespace.c:3585 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0ab0f85d29 RSP: 002b:00007f0ab1d3a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f0ab1176080 RCX: 00007f0ab0f85d29 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000000 RBP: 00007f0ab1001aa8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f0ab1176080 R15: 00007ffee7e990f8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c927eb0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c9286d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8c927520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c927520 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c927520 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 4 locks held by kworker/u4:2/34: #0: ffff888017216938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78e/0x1160 kernel/workqueue.c:2267 #1: ffffc90000ab7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x78e/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dae6b90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffffffff8c92d080 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x600 kernel/rcu/tree.c:4019 7 locks held by kworker/u4:3/46: 1 lock held by kswapd0/83: 1 lock held by dhcpcd/3919: #0: ffffffff8daf3128 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2287 2 locks held by getty/4012: #0: ffff888030116098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ca/0x1a60 drivers/tty/n_tty.c:2198 2 locks held by kworker/1:10/4986: #0: ffff888017072138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78e/0x1160 kernel/workqueue.c:2267 #1: ffffc900032a7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x78e/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/1:12/4988: #0: ffff88802fa6ad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x78e/0x1160 kernel/workqueue.c:2267 #1: ffffc900032d7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x78e/0x1160 kernel/workqueue.c:2267 #2: ffffffff8daf3128 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x15/0x30 net/ipv6/addrconf.c:4675 1 lock held by syz.4.20/5105: 1 lock held by syz.4.20/5111: #0: ffff8880562a8188 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff8880562a8188 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1706 2 locks held by syz.2.18/5215: 1 lock held by syz.2.18/5218: #0: ffff8880562a86d0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff8880562a86d0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1706 2 locks held by syz.0.16/5221: 1 lock held by syz.0.16/5226: #0: ffff88804a518188 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff88804a518188 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1706 1 lock held by syz.1.17/5223: 1 lock held by syz.1.17/5227: #0: ffff88804a5186d0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff88804a5186d0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1706 1 lock held by syz.3.19/5229: 1 lock held by syz.3.19/5231: #0: ffff8880562a8c18 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff8880562a8c18 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1706 5 locks held by syz.5.21/5369: 1 lock held by syz.5.21/5373: #0: ffff8880562a9160 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff8880562a9160 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1706 3 locks held by kworker/u4:8/5425: #0: ffff888017079138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x78e/0x1160 kernel/workqueue.c:2267 #1: ffffc900040b7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x78e/0x1160 kernel/workqueue.c:2267 #2: ffffffff8daf3128 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 1 lock held by syz.8.24/5525: 1 lock held by syz.8.24/5527: #0: ffff8880562a96a8 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff8880562a96a8 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1706 1 lock held by syz.6.22/5532: 1 lock held by syz.6.22/5536: #0: ffff88804a518c18 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff88804a518c18 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1706 1 lock held by syz.9.25/5535: 1 lock held by syz.9.25/5539: #0: ffff8880562a9bf0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff8880562a9bf0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1706 1 lock held by syz.7.23/5541: 1 lock held by syz.7.23/5543: #0: ffff8880562aa138 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff8880562aa138 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1706 2 locks held by udevd/5600: 1 lock held by udevd/5602: 1 lock held by syz-executor/6157: #0: ffffffff8daf3128 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8daf3128 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6150 2 locks held by syz-executor/6163: #0: ffffffff8daf3128 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8daf3128 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6150 #1: ffffffff8c92d1b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffffffff8c92d1b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 1 lock held by syz-executor/6164: #0: ffffffff8daf3128 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8daf3128 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6150 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 6.1.138-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x19a/0x3e0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.1.138-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:dst_destroy+0x26c/0x2f0 net/core/dst.c:123 Code: 63 f9 85 ed 74 07 e8 53 6e 63 f9 eb 11 e8 4c 6e 63 f9 48 8d bb c0 00 00 00 e8 b0 e7 11 00 48 89 df e8 38 d9 9c f9 48 8b 1c 24 <48> 85 db 74 0f e8 2a 6e 63 f9 48 89 df e8 f2 00 00 00 eb 05 e8 1b RSP: 0018:ffffc90000147a00 EFLAGS: 00000286 RAX: 068f636049e94f00 RBX: 0000000000000000 RCX: 068f636049e94f00 RDX: dffffc0000000000 RSI: ffffffff8a6be420 RDI: ffffffff8abe1040 RBP: 0000000000000000 R08: ffff88823b400000 R09: 0000000000000001 R10: 0000000028aeb17f R11: 1ffff92000028ebf R12: ffff88801dfb92b8 R13: dffffc0000000000 R14: ffff88801dfb9288 R15: ffff888023b841f8 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558df13808 CR3: 000000005840a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0x9c0/0x16a0 kernel/rcu/tree.c:2557 handle_softirqs+0x2a1/0x920 kernel/softirq.c:578 run_ksoftirqd+0x98/0xf0 kernel/softirq.c:945 smpboot_thread_fn+0x64a/0xa40 kernel/smpboot.c:164 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295