INFO: task syz.3.4553:5948 blocked for more than 143 seconds. Tainted: G U 6.14.0-rc4-syzkaller-00090-gdd83757f6e68 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.4553 state:D stack:26560 pid:5948 tgid:5945 ppid:3423 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730 nfsd_nl_version_set_doit+0xc5/0x7a0 fs/nfsd/nfsctl.c:1771 genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2543 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627 __sys_sendmsg+0x16e/0x220 net/socket.c:2659 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f17a518d169 RSP: 002b:00007f17a5fcb038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f17a53a5fa0 RCX: 00007f17a518d169 RDX: 000000000000c010 RSI: 00004000000004c0 RDI: 0000000000000006 RBP: 00007f17a520e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f17a53a5fa0 R15: 00007ffe1161c528 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e1bccc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bccc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bccc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 2 locks held by kworker/u8:11/6116: 2 locks held by kworker/u8:20/10969: #0: ffff8881413cd148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc9000ecafd18 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 4 locks held by kworker/u8:29/15699: #0: ffff88801bef5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc90002e77d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8fee3210 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xca/0xb30 net/core/net_namespace.c:606 #3: ffffffff8e1c8138 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:302 2 locks held by syz-executor/27022: #0: ffff888070c1a0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888070c1a0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888070c1a0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e5bfe68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/28062: #0: ffff888047fa80e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888047fa80e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888047fa80e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e5bfe68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by getty/1257: #0: ffff88803524a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90003d332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 2 locks held by syz.6.4387/3029: #0: ffffffff8ff99c30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5bfe68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xe3/0x1b40 fs/nfsd/nfsctl.c:1922 2 locks held by syz.3.4553/5948: #0: ffffffff8ff99c30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5bfe68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xc5/0x7a0 fs/nfsd/nfsctl.c:1771 2 locks held by syz-executor/9877: #0: ffff88801bb040e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88801bb040e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88801bb040e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e5bfe68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 4 locks held by syz.1.5132/15646: 5 locks held by syz.1.5142/15784: 2 locks held by syz.1.5142/15851: 2 locks held by syz.2.5146/15894: 2 locks held by syz.5.5147/15918: #0: ffffffff8fee3210 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:512 #1: ffffffff8fef8ea8 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x1b/0x70 net/ipv4/nexthop.c:3878 1 lock held by syz.4.5148/15930: #0: ffffffff8ee898a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8ee898a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129 2 locks held by sed/15932: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G U 6.14.0-rc4-syzkaller-00090-gdd83757f6e68 #0 Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0xf62/0x12b0 kernel/hung_task.c:399 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 15894 Comm: syz.2.5146 Tainted: G U 6.14.0-rc4-syzkaller-00090-gdd83757f6e68 #0 Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:unwind_next_frame+0x631/0x20c0 arch/x86/kernel/unwind_orc.c:581 Code: 0f 95 c6 40 84 f7 0f 85 3a 1a 00 00 83 e0 07 38 c2 40 0f 9e c6 84 d2 0f 95 c0 40 84 c6 0f 85 23 1a 00 00 4c 0f bf 31 4d 01 fe <0f> b6 41 05 83 e0 07 3c 03 0f 84 fd 08 00 00 3c 04 0f 84 2e 08 00 RSP: 0018:ffffc90010fbf078 EFLAGS: 00000286 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff910223ee RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffc90010fbf130 R08: ffffffff91022424 R09: ffffffff910223f2 R10: ffffc90010fbf0e8 R11: 000000000001032e R12: ffffc90010fbf138 R13: ffffc90010fbf0e8 R14: ffffc90010fbfa78 R15: ffffc90010fbfa28 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe03e74c270 CR3: 000000008699e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x95/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 save_stack+0x162/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x8d/0x400 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_folios+0xa7b/0x1500 mm/page_alloc.c:2707 folios_put_refs+0x587/0x7b0 mm/swap.c:994 free_pages_and_swap_cache+0x351/0x500 mm/swap_state.c:331 __tlb_batch_free_encoded_pages+0xf9/0x290 mm/mmu_gather.c:136 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:389 [inline] tlb_flush_mmu+0xe9/0x590 mm/mmu_gather.c:396 zap_pte_range mm/memory.c:1781 [inline] zap_pmd_range mm/memory.c:1834 [inline] zap_pud_range mm/memory.c:1863 [inline] zap_p4d_range mm/memory.c:1884 [inline] unmap_page_range+0x1dec/0x4390 mm/memory.c:1905 unmap_single_vma+0x194/0x2b0 mm/memory.c:1951 unmap_vmas+0x22f/0x490 mm/memory.c:1995 exit_mmap+0x1c1/0xba0 mm/mmap.c:1284 __mmput+0x12a/0x410 kernel/fork.c:1356 mmput+0x62/0x70 kernel/fork.c:1378 exit_mm kernel/exit.c:570 [inline] do_exit+0x9ba/0x2d70 kernel/exit.c:925 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096 x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fda96d8d169 Code: Unable to access opcode bytes at 0x7fda96d8d13f. RSP: 002b:00007fff26d01078 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fda96d8d169 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff26d010dc R08: 0000001826d0116f R09: 00000000000927c0 R10: 0000000000025b74 R11: 0000000000000246 R12: 0000000000000099 R13: 00000000000927c0 R14: 0000000000127c18 R15: 00007fff26d01130