INFO: task syz.2.5427:18551 blocked for more than 143 seconds. Tainted: G L syzkaller #0 task:syz.2.5427 state:D stack:26920 pid:18551 tgid:18549 ppid:5824 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x169e/0x54f0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563 rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1659 __rt_mutex_slowlock kernel/locking/rtmutex.c:1736 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1776 [inline] rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1816 __rt_mutex_lock kernel/locking/rtmutex.c:1831 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:553 nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1788 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x780/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:786 [inline] __sock_sendmsg net/socket.c:801 [inline] ____sys_sendmsg+0x94c/0x9c0 net/socket.c:2650 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2704 __sys_sendmsg net/socket.c:2736 [inline] __do_sys_sendmsg net/socket.c:2741 [inline] __se_sys_sendmsg net/socket.c:2739 [inline] __x64_sys_sendmsg+0x1c3/0x2a0 net/socket.c:2739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f68678fc819 RSP: 002b:00007f6865b56028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f6867b75fa0 RCX: 00007f68678fc819 RDX: 0000000004008090 RSI: 0000200000000140 RDI: 0000000000000003 RBP: 00007f6867992c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6867b76038 R14: 00007f6867b75fa0 R15: 00007ffefff672d8 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8e3c80c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e3c80c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e3c80c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 2 locks held by getty/5583: #0: ffff888028fbc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 3 locks held by syz-executor/5826: #0: ffffffff8e4991d0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1533 [inline] #0: ffffffff8e4991d0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x130/0x4a0 kernel/fork.c:1586 #1: ffff88803a699db0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline] #1: ffff88803a699db0 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x181/0x1d50 mm/mmap.c:1739 #2: ffff888028b3d1b0 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:544 [inline] #2: ffff888028b3d1b0 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x26f/0x1d50 mm/mmap.c:1746 3 locks held by kworker/0:6/5937: #0: ffff88813ff5f938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3280 [inline] #0: ffff88813ff5f938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa2e/0x1910 kernel/workqueue.c:3399 #1: ffffc900059b7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3281 [inline] #1: ffffc900059b7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa69/0x1910 kernel/workqueue.c:3399 #2: ffff888036b73260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490 2 locks held by syz.1.5186/17952: #0: ffffffff8f80f200 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8e6ea338 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x13e/0x1630 fs/nfsd/nfsctl.c:1938 2 locks held by syz.2.5427/18551: #0: ffffffff8f80f200 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8e6ea338 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1788 1 lock held by syz-executor/18740: #0: ffffffff8e3c80c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e3c80c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e3c80c0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline] #0: ffffffff8e3c80c0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495 2 locks held by syz.5.7137/23812: #0: ffffffff8f80f200 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8e6ea338 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x13e/0x1630 fs/nfsd/nfsctl.c:1938 1 lock held by syz-executor/24650: #0: ffff888036ba2958 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #0: ffff888036ba2958 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3736 [inline] #0: ffff888036ba2958 (&n->list_lock){+.+.}-{3:3}, at: __refill_objects_node+0x87/0x560 mm/slub.c:7103 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 18740 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1109 [inline] RIP: 0010:debug_check_no_obj_freed+0x21b/0x550 lib/debugobjects.c:1146 Code: 48 89 04 24 4c 8d 7d 18 4c 89 f8 48 c1 e8 03 80 3c 10 00 74 12 4c 89 ff e8 22 ef 6f fd 48 ba 00 00 00 00 00 fc ff df 4d 8b 3f <4d> 39 ef 0f 92 c0 4d 39 fc 0f 96 c1 08 c1 75 90 4c 8d 6d 10 4c 89 RSP: 0018:ffffc9000e8af9b0 EFLAGS: 00000046 RAX: 1ffff11009e417ca RBX: 0000000000000001 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffc9000e8af920 RBP: ffff88804f20be38 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52001d15f24 R12: ffff888031d02520 R13: ffff888031d02500 R14: 1ffff11009e417c7 R15: ffff888031d02dc0 FS: 0000555562c22500(0000) GS:ffff888125b6b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe147537dac CR3: 000000005fe56000 CR4: 00000000003526f0 Call Trace: slab_free_hook mm/slub.c:2620 [inline] slab_free mm/slub.c:6246 [inline] kfree+0x13e/0x6c0 mm/slub.c:6561 tomoyo_path_perm+0x403/0x560 security/tomoyo/file.c:847 tomoyo_path_unlink+0xaa/0xf0 security/tomoyo/tomoyo.c:162 security_path_unlink+0x15f/0x330 security/security.c:1483 filename_unlinkat+0x34f/0x610 fs/namei.c:5565 __do_sys_unlink fs/namei.c:5603 [inline] __se_sys_unlink+0x2e/0x140 fs/namei.c:5600 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f43c353b907 Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007fff5ae5d228 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f43c353b907 RDX: 00007fff5ae5d250 RSI: 00007fff5ae5d2e0 RDI: 00007fff5ae5d2e0 RBP: 00007fff5ae5d2e0 R08: 00007fff5ae5e2e0 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007fff5ae5e370 R13: 00007f43c35d2048 R14: 000000000008eb6d R15: 00007fff5ae5e3b0