INFO: task syz-executor:17471 blocked for more than 143 seconds. Not tainted 6.16.0-rc4-syzkaller-00348-g772b78c2abd8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:24168 pid:17471 tgid:17471 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6883 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6940 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1386 deactivate_locked_super+0xc1/0x1a0 fs/super.c:474 deactivate_super fs/super.c:507 [inline] deactivate_super+0xde/0x100 fs/super.c:503 cleanup_mnt+0x225/0x450 fs/namespace.c:1417 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x490 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f001d58fc57 RSP: 002b:00007fff7b053648 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f001d610925 RCX: 00007f001d58fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff7b054790 RBP: 00007fff7b05477c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff7b054790 R13: 00007f001d610925 R14: 000000000011ead9 R15: 00007fff7b0547d0 INFO: task syz.2.3198:22220 blocked for more than 143 seconds. Not tainted 6.16.0-rc4-syzkaller-00348-g772b78c2abd8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.3198 state:D stack:27336 pid:22220 tgid:22218 ppid:17747 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6883 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6940 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 nfsd_nl_listener_get_doit+0x13e/0x7b0 fs/nfsd/nfsctl.c:2076 genl_family_rcv_msg_doit+0x206/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2534 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2566 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620 __sys_sendmsg+0x16d/0x220 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f900d18e929 RSP: 002b:00007f900aff6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f900d3b6080 RCX: 00007f900d18e929 RDX: 0000000000004010 RSI: 0000200000002680 RDI: 0000000000000009 RBP: 00007f900d210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f900d3b6080 R15: 00007ffe3e1faea8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 1 lock held by klogd/5206: #0: ffff8880b843a418 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:614 [inline] #0: ffff8880b843a418 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:599 1 lock held by udevd/5217: #0: ffff8880b843a418 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:614 [inline] #0: ffff8880b843a418 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:599 2 locks held by syz-executor/17471: #0: ffff8880318a60e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880318a60e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880318a60e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff8880318a60e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503 #1: ffffffff8e9de188 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/18130: #0: ffff88805c7f80e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805c7f80e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805c7f80e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88805c7f80e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503 #1: ffffffff8e9de188 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz.3.3047/21504: #0: ffffffff90407e30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e9de188 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xdd/0x1a40 fs/nfsd/nfsctl.c:1922 2 locks held by syz-executor/21780: #0: ffff888062f020e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888062f020e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888062f020e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff888062f020e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503 #1: ffffffff8e9de188 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz.2.3198/22220: #0: ffffffff90407e30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e9de188 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x13e/0x7b0 fs/nfsd/nfsctl.c:2076 2 locks held by syz.6.3301/22746: #0: ffffffff90407e30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e9de188 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629 2 locks held by syz-executor/22952: #0: ffff888082e080e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888082e080e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888082e080e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff888082e080e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503 #1: ffffffff8e9de188 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by getty/24370: #0: ffff888035f220a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000343b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz.9.3631/24387: #0: ffff888028b065e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:374 [inline] #0: ffff888028b065e0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1d8/0x450 mm/util.c:577 2 locks held by syz.9.3631/24388: 1 lock held by syz.9.3631/24389: #0: ffff888028b065e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable include/linux/mmap_lock.h:421 [inline] #0: ffff888028b065e0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:197 [inline] #0: ffff888028b065e0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x3e7/0x6e0 mm/mmap_lock.c:248 1 lock held by syz.9.3631/24390: 1 lock held by syz.9.3631/24399: #0: ffff888028b065e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable include/linux/mmap_lock.h:421 [inline] #0: ffff888028b065e0 (&mm->mmap_lock){++++}-{4:4}, at: __get_user_pages_locked mm/gup.c:1809 [inline] #0: ffff888028b065e0 (&mm->mmap_lock){++++}-{4:4}, at: faultin_page_range+0x33b/0x980 mm/gup.c:1978 2 locks held by syz.9.3631/24407: #0: ffffffff9034d5d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 #1: ffffffff90363628 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #1: ffffffff90363628 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11218 2 locks held by syz.9.3631/24415: 1 lock held by syz.9.3631/24416: #0: ffff888028b065e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff888028b065e0 (&mm->mmap_lock){++++}-{4:4}, at: __mm_populate+0x21f/0x380 mm/gup.c:2008 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-syzkaller-00348-g772b78c2abd8 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 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: 5217 Comm: udevd Not tainted 6.16.0-rc4-syzkaller-00348-g772b78c2abd8 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:cred_label security/apparmor/include/cred.h:24 [inline] RIP: 0010:aa_cred_raw_label security/apparmor/include/cred.h:49 [inline] RIP: 0010:aa_current_raw_label security/apparmor/include/cred.h:96 [inline] RIP: 0010:__begin_current_label_crit_section security/apparmor/include/cred.h:147 [inline] RIP: 0010:common_perm security/apparmor/lsm.c:225 [inline] RIP: 0010:common_perm_dir_dentry security/apparmor/lsm.c:273 [inline] RIP: 0010:common_perm_create security/apparmor/lsm.c:320 [inline] RIP: 0010:apparmor_path_mknod+0x235/0x460 security/apparmor/lsm.c:343 Code: 4c 8b a5 b0 08 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d bc 24 80 00 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 e0 01 00 00 <48> 63 2d 34 21 5f 09 49 03 ac 24 80 00 00 00 0f 84 4e 01 00 00 e8 RSP: 0018:ffffc9000eff7850 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 1ffff92001dfef0a RCX: ffffffff8495bb70 RDX: 1ffff11006641070 RSI: ffffffff8495bbc3 RDI: ffff888033208380 RBP: ffff8880488f1e00 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888033208300 R13: ffff88805cbe3490 R14: 0000000000000000 R15: dffffc0000000000 FS: 00007fdbb7618880(0000) GS:ffff888124823000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000140 CR3: 0000000035538000 CR4: 00000000003526f0 Call Trace: security_path_mknod+0x18d/0x310 security/security.c:1899 may_o_create fs/namei.c:3536 [inline] lookup_open.isra.0+0xc17/0x1580 fs/namei.c:3680 open_last_lookups fs/namei.c:3816 [inline] path_openat+0x893/0x2cb0 fs/namei.c:4052 do_filp_open+0x20b/0x470 fs/namei.c:4082 do_sys_openat2+0x11b/0x1d0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdbb6ea7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffd65334390 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fdbb7618880 RCX: 00007fdbb6ea7407 RDX: 0000000000080141 RSI: 000055d03845c02e RDI: ffffffffffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001a4 R11: 0000000000000202 R12: 00000000ffffffff R13: 00000000ffffffff R14: ffffffffffffffff R15: 0000000000000000