INFO: task syz-executor:5836 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21832 pid:5836 tgid:5836 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 netfs_wait_for_outstanding_io include/linux/netfs.h:552 [inline] v9fs_evict_inode+0x170/0x320 fs/9p/vfs_inode.c:348 evict+0x501/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 shrink_dcache_for_umount+0xa0/0x170 fs/dcache.c:1621 generic_shutdown_super+0x67/0x2c0 fs/super.c:621 kill_anon_super+0x3b/0x70 fs/super.c:1282 v9fs_kill_super+0x4c/0x90 fs/9p/vfs_super.c:195 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fef75be01f7 RSP: 002b:00007ffd17f5bef8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fef75c61d7d RCX: 00007fef75be01f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd17f5bfb0 RBP: 00007ffd17f5bfb0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd17f5d040 R13: 00007fef75c61d7d R14: 00000000000ab521 R15: 00007ffd17f5d080 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5596: #0: ffff88823bf540a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5836: #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 4 locks held by kworker/1:5/5924: #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc900050a7bc0 (kernfs_notify_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900050a7bc0 (kernfs_notify_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff88801988c348 (&root->kernfs_supers_rwsem){++++}-{4:4}, at: kernfs_notify_workfn+0xed/0x5f0 fs/kernfs/file.c:932 #3: ffff88801988c238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_notify_workfn+0x101/0x5f0 fs/kernfs/file.c:933 2 locks held by kworker/u8:14/5974: 9 locks held by kworker/1:8/6462: 1 lock held by syz.7.1664/12081: #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.7.1664/12082: #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.7.1664/12086: #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.7.1664/12090: #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.7.1664/12095: #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.7.1664/12096: #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.7.1664/12098: #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.7.1664/12101: #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888010c7e0d0 (&type->s_umount_key#85){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 3 locks held by syz-executor/12255: #0: ffffffff8e43b9e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e43b9e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e43b9e0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 #2: ffff88801988c238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x41/0x520 fs/kernfs/dir.c:791 6 locks held by syz.6.1755/12432: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12432 Comm: syz.6.1755 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:lock_is_held include/linux/lockdep.h:249 [inline] RIP: 0010:rtlock_slowlock_locked+0xb0/0x4010 kernel/locking/rtmutex.c:1836 Code: 3b 16 f3 f3 48 c7 c0 40 74 1d 8f 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 ee 3a 00 00 83 3d d7 ef 23 04 00 74 17 49 8d 7c 24 18 ff ff ff ff e8 36 90 fd ff 85 c0 0f 84 4d 05 00 00 65 4c 8b 34 RSP: 0018:ffffc90005f9f360 EFLAGS: 00000002 RAX: 0000000000000000 RBX: 1ffff92000bf3e94 RCX: dffffc0000000000 RDX: 0000000000000001 RSI: ffffc90005f9f600 RDI: ffff888077430c58 RBP: ffffc90005f9f5b0 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000bf3e94 R12: ffff888077430c40 R13: ffffc90005f9f608 R14: 1ffff92000bf3ec1 R15: dffffc0000000000 FS: 00007f1901ea56c0(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000015030 CR3: 000000006ea18000 CR4: 00000000003526f0 Call Trace: rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x152/0x2c0 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:44 [inline] __skb_try_recv_datagram+0x89/0x1b0 net/core/datagram.c:264 __unix_dgram_recvmsg+0x2d4/0xd60 net/unix/af_unix.c:2601 sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1065 ____sys_recvmsg+0x3ab/0x470 net/socket.c:2832 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2876 do_recvmmsg+0x30d/0x770 net/socket.c:2971 __sys_recvmmsg net/socket.c:3045 [inline] __do_sys_recvmmsg net/socket.c:3068 [inline] __se_sys_recvmmsg net/socket.c:3061 [inline] __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3061 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1903c5eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1901ea5038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f1903eb6090 RCX: 00007f1903c5eec9 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f1903ce1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1903eb6128 R14: 00007f1903eb6090 R15: 00007ffd5c228ff8