INFO: task syz.3.1421:12612 blocked for more than 143 seconds. Not tainted 6.14.0-rc4-syzkaller-00212-g276f98efb64a #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1421 state:D stack:26960 pid:12612 tgid:12611 ppid:5833 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_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629 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:2533 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1882 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: 0033:0x7f1b1f58d169 RSP: 002b:00007f1b203a0038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f1b1f7a5fa0 RCX: 00007f1b1f58d169 RDX: 0000000000000840 RSI: 0000400000000240 RDI: 0000000000000004 RBP: 00007f1b1f60e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1b1f7a5fa0 R15: 00007fff4ae17f38 INFO: task syz.2.1438:12715 blocked for more than 144 seconds. Not tainted 6.14.0-rc4-syzkaller-00212-g276f98efb64a #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1438 state:D stack:26800 pid:12715 tgid:12713 ppid:5832 task_flags:0x400140 flags:0x00020004 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_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629 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:2533 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1882 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: 0033:0x7f58b078d169 RSP: 002b:00007f58b15a1038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f58b09a5fa0 RCX: 00007f58b078d169 RDX: 0000000000000810 RSI: 0000400000002640 RDI: 000000000000000c RBP: 00007f58b080e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f58b09a5fa0 R15: 00007fff305045f8 Showing all locks held in the system: 3 locks held by kworker/0:1/9: #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc900000e7d18 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8e1c8000 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x700 kernel/rcu/tree.c:3741 2 locks held by kworker/u8:0/11: #0: ffff888147eb9948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc90000107d18 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 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 3 locks held by kworker/u8:7/5016: 2 locks held by getty/5597: #0: ffff88803141f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5823: #0: ffff8880b873ed58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:598 2 locks held by syz-executor/5834: #0: ffff8880526960e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880526960e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880526960e0 (&type->s_umount_key#51){+.+.}-{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 3 locks held by kworker/u9:2/5837: #0: ffff888090f62148 ((wq_completion)hci9){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc90003eafd18 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffff88807b3b0d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x170/0x410 net/bluetooth/hci_sync.c:331 2 locks held by kworker/u8:10/6973: 2 locks held by kworker/u8:34/7347: #0: ffff888147eb9948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc90018eb7d18 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 2 locks held by kworker/u8:42/7355: #0: ffff888147eb9948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc900107f7d18 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 2 locks held by syz.3.1421/12612: #0: ffffffff8ff9a0b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5bfe68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629 2 locks held by syz.1.1423/12626: #0: ffffffff8ff9a0b0 (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-executor/12664: #0: ffff8880796040e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880796040e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880796040e0 (&type->s_umount_key#51){+.+.}-{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/12685: #0: ffff88805ea380e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88805ea380e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88805ea380e0 (&type->s_umount_key#51){+.+.}-{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.2.1438/12715: #0: ffffffff8ff9a0b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5bfe68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629 2 locks held by syz-executor/12830: #0: ffff888060ee80e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888060ee80e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888060ee80e0 (&type->s_umount_key#51){+.+.}-{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/12863: #0: ffff88802781c0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88802781c0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88802781c0e0 (&type->s_umount_key#51){+.+.}-{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/12893: #0: ffff888012f580e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888012f580e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888012f580e0 (&type->s_umount_key#51){+.+.}-{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/12953: #0: ffff88807cf880e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807cf880e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807cf880e0 (&type->s_umount_key#51){+.+.}-{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/13059: #0: ffff8880624720e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880624720e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880624720e0 (&type->s_umount_key#51){+.+.}-{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/13069: #0: ffff8880213320e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880213320e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880213320e0 (&type->s_umount_key#51){+.+.}-{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.3.1503/13082: #0: ffffffff8ff9a0b0 (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-executor/13206: #0: ffff8880312c20e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880312c20e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880312c20e0 (&type->s_umount_key#51){+.+.}-{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 1 lock held by syz.6.1706/14094: 4 locks held by syz.5.1734/14214: 3 locks held by syz.8.1736/14226: 3 locks held by syz.5.1740/14245: #0: ffff88807718f7b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1192 #1: ffff888025240420 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffffffff8e5bfe68 (nfsd_mutex){+.+.}-{4:4}, at: expkey_flush+0x18/0x90 fs/nfsd/export.c:252 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc4-syzkaller-00212-g276f98efb64a #0 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: 14226 Comm: syz.8.1736 Not tainted 6.14.0-rc4-syzkaller-00212-g276f98efb64a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:write_comp_data+0x3c/0x90 kernel/kcov.c:246 Code: 8b 05 70 01 4a 7e a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 0f 00 75 60 a9 00 00 f0 00 75 59 8b 82 2c 16 00 00 85 c0 74 4f <8b> 82 08 16 00 00 83 f8 03 75 44 48 8b 82 10 16 00 00 8b 92 0c 16 RSP: 0018:ffffc9001847ed88 EFLAGS: 00000246 RAX: 0000000080000000 RBX: ffffea00010b9480 RCX: ffffffff81f8fc26 RDX: ffff88805f293c00 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000002 R12: ffff8880aa728a28 R13: 000000000000651c R14: 0000000000000000 R15: 0000000000000000 FS: 00007f3e52e5f6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000003000000 CR3: 00000000ab5fc000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: const_folio_flags.constprop.0+0x36/0x70 include/linux/page-flags.h:310 folio_test_head include/linux/page-flags.h:829 [inline] folio_test_large include/linux/page-flags.h:850 [inline] folio_order include/linux/mm.h:1128 [inline] shmem_add_to_page_cache+0x2fe/0x9b0 mm/shmem.c:873 shmem_alloc_and_add_folio+0x662/0xc10 mm/shmem.c:1928 shmem_get_folio_gfp+0x689/0x1530 mm/shmem.c:2522 shmem_get_folio mm/shmem.c:2628 [inline] shmem_write_begin+0x161/0x300 mm/shmem.c:3278 generic_perform_write+0x2ba/0x920 mm/filemap.c:4189 shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3454 __kernel_write_iter+0x318/0xa90 fs/read_write.c:612 dump_emit_page fs/coredump.c:884 [inline] dump_user_range+0x389/0x8c0 fs/coredump.c:945 elf_core_dump+0x287c/0x3a50 fs/binfmt_elf.c:2129 do_coredump+0x3134/0x4400 fs/coredump.c:758 get_signal+0x230b/0x26c0 kernel/signal.c:3021 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x1000 Code: Unable to access opcode bytes at 0xfd6. RSP: 002b:000000000000000f EFLAGS: 00010282 RAX: 0000000000000003 RBX: 00007f3e521a5fa0 RCX: 00007f3e51f8d169 RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000020003b46 RBP: 00007f3e5200e2a0 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3e521a5fa0 R15: 00007fff44c73ae8