INFO: task syz.1.630:9116 blocked for more than 144 seconds. Not tainted 6.12.0-next-20241120-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.630 state:D stack:27296 pid:9116 tgid:9102 ppid:5842 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 rwsem_down_read_slowpath kernel/locking/rwsem.c:1084 [inline] __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x705/0xa40 kernel/locking/rwsem.c:1526 inode_lock_shared include/linux/fs.h:828 [inline] lookup_slow+0x45/0x70 fs/namei.c:1807 walk_component+0x2e1/0x410 fs/namei.c:2112 lookup_last fs/namei.c:2610 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2634 filename_lookup+0x2a3/0x670 fs/namei.c:2663 user_path_at+0x3a/0x60 fs/namei.c:3070 do_mount fs/namespace.c:3844 [inline] __do_sys_mount fs/namespace.c:4057 [inline] __se_sys_mount+0x297/0x3c0 fs/namespace.c:4034 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: 0033:0x7f12e257e819 RSP: 002b:00007f12e32b1038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f12e2736080 RCX: 00007f12e257e819 RDX: 0000000020000000 RSI: 0000000020000080 RDI: 0000000000000000 RBP: 00007f12e25f175e R08: 00000000200002c0 R09: 0000000000000000 R10: 0000000000010000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f12e2736080 R15: 00007ffc2f803a98 Showing all locks held in the system: 1 lock held by ksoftirqd/0/16: 1 lock held by khungtaskd/30: #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 2 locks held by getty/5595: #0: ffff8880318030a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fc62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by kworker/0:4/5888: 5 locks held by kworker/0:7/5927: 3 locks held by kworker/u8:10/6382: 3 locks held by syz.1.630/9103: 1 lock held by syz.1.630/9116: #0: ffff888056e815f0 (&sb->s_type->i_mutex_key#32){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:828 [inline] #0: ffff888056e815f0 (&sb->s_type->i_mutex_key#32){++++}-{4:4}, at: lookup_slow+0x45/0x70 fs/namei.c:1807 1 lock held by syz.3.874/10237: 2 locks held by syz.9.871/10238: #0: ffffffff8fca0ac8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fca0ac8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 #1: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #1: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 2 locks held by syz.7.876/10247: 2 locks held by syz.4.872/10255: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-next-20241120-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 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+0xffb/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: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-next-20241120-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3817 [inline] RIP: 0010:validate_chain+0x1cb/0x5920 kernel/locking/lockdep.c:3872 Code: 8d 1c c5 c0 a7 df 93 48 89 d8 48 c1 e8 03 48 89 44 24 68 42 80 3c 20 00 74 08 48 89 df e8 3d 07 8f 00 48 89 5c 24 48 48 8b 1b <48> 85 db 74 48 48 83 c3 f8 74 42 4c 8d 7b 18 4c 89 f8 48 c1 e8 03 RSP: 0018:ffffc90000156da0 EFLAGS: 00000046 RAX: 1ffffffff28203a6 RBX: ffffffff94442328 RCX: ffffffff817b63be RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff9428a8f8 RBP: ffffc900001570a0 R08: ffffffff9428a8ff R09: 1ffffffff285151f R10: dffffc0000000000 R11: fffffbfff2851520 R12: dffffc0000000000 R13: ffff88801cace528 R14: 7ff3fc5e9a383ce7 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d119ff8 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] usb_hcd_link_urb_to_ep+0x2f/0x310 drivers/usb/core/hcd.c:1134 dummy_urb_enqueue+0x290/0x780 drivers/usb/gadget/udc/dummy_hcd.c:1287 usb_hcd_submit_urb+0x36c/0x1e80 drivers/usb/core/hcd.c:1533 ath9k_hif_usb_rx_cb+0x11f7/0x1590 drivers/net/wireless/ath/ath9k/hif_usb.c:722 __usb_hcd_giveback_urb+0x42c/0x6e0 drivers/usb/core/hcd.c:1650 dummy_timer+0x856/0x4620 drivers/usb/gadget/udc/dummy_hcd.c:1993 __run_hrtimer kernel/time/hrtimer.c:1739 [inline] __hrtimer_run_queues+0x59b/0xd50 kernel/time/hrtimer.c:1803 hrtimer_run_softirq+0x19a/0x2c0 kernel/time/hrtimer.c:1820 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:943 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 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