INFO: task syz.2.208:6705 blocked for more than 143 seconds. Not tainted 6.15.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.208 state:D stack:26600 pid:6705 tgid:6704 ppid:5840 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746 nfsd_nl_threads_set_doit+0x698/0xbf0 fs/nfsd/nfsctl.c:1629 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+0x16a/0x440 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+0xa95/0xc70 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/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8bf3d8d169 RSP: 002b:00007f8bf1bf6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f8bf3fa5fa0 RCX: 00007f8bf3d8d169 RDX: 0000000000000810 RSI: 0000200000000040 RDI: 0000000000000003 RBP: 00007f8bf3e0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8bf3fa5fa0 R15: 00007ffdc02101e8 Showing all locks held in the system: 3 locks held by kworker/0:0/9: 1 lock held by khungtaskd/31: #0: ffffffff8e3c1580 ( rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764 2 locks held by syz-executor/5849: #0: ffff8880452860e0 ( &type->s_umount_key #48 ){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] ){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] ){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] ){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/5851: #0: ffff888034be60e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888034be60e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888034be60e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff888034be60e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 3 locks held by kworker/u8:22/6459: #0: ffff88814d225948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003eafd18 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1155 [inline] #2: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x20a0 arch/x86/kernel/unwind_orc.c:479 6 locks held by kworker/u8:32/6571: 2 locks held by kworker/u8:33/6572: 2 locks held by syz.3.205/6700: #0: ffffffff901cfa10 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x698/0xbf0 fs/nfsd/nfsctl.c:1629 2 locks held by syz.2.208/6705: #0: ffffffff901cfa10 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x698/0xbf0 fs/nfsd/nfsctl.c:1629 2 locks held by syz-executor/6927: #0: ffff88804587e0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88804587e0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88804587e0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88804587e0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/6934: #0: ffff88803ba360e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88803ba360e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88803ba360e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88803ba360e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by getty/7004: #0: ffff888035a3a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000b12b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/7614: #0: ffff88805ab620e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88805ab620e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88805ab620e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88805ab620e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/7623: #0: ffff88805b06c0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88805b06c0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88805b06c0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88805b06c0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz.6.488/7805: #0: ffff888042de40e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888042de40e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888042de40e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff888042de40e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/7824: #0: ffff88814e4880e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88814e4880e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88814e4880e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88814e4880e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/7968: #0: ffff888061c840e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888061c840e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888061c840e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff888061c840e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/7999: #0: ffff88808c73a0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88808c73a0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88808c73a0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88808c73a0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/8031: #0: ffff8880900740e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880900740e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880900740e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff8880900740e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/8058: #0: ffff888078c960e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888078c960e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888078c960e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff888078c960e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/8148: #0: ffff88808c29a0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88808c29a0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88808c29a0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88808c29a0e0 (&type->s_umount_key#48){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd1e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 1 lock held by syz-executor/8256: #0: ffffffff8e3ccab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x280/0x3c0 kernel/rcu/tree_exp.h:304 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:437 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 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: 8256 Comm: syz-executor Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x2c/0xc0 kernel/rcu/tree.c:736 Code: 1e fa 55 53 65 ff 05 43 88 05 12 e8 be 14 cf 09 48 c7 c3 e8 9d a7 93 89 c5 83 f8 07 0f 87 82 00 00 00 48 8d 3c ed 00 6d cf 8d <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 RSP: 0018:ffffc9000b017690 EFLAGS: 00000297 RAX: 0000000000000000 RBX: ffffffff93a79de8 RCX: ffffffff81cb4b4e RDX: ffff8880280b3c00 RSI: ffffffff8bf45080 RDI: ffffffff8dcf6d00 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81cb4aaa R13: ffffc9000b017808 R14: 0000000000000000 R15: ffff8880280b3c00 FS: 0000000000000000(0000) GS:ffff8881249b9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a00ae75088 CR3: 000000000e182000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x201/0x2f0 kernel/locking/lockdep.c:5877 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] is_bpf_text_address+0x8f/0x1a0 kernel/bpf/core.c:774 kernel_text_address kernel/extable.c:125 [inline] kernel_text_address+0x8d/0x100 kernel/extable.c:94 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x59/0xa0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xa6/0x100 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2680 vfree+0x176/0x960 mm/vmalloc.c:3383 kcov_put kernel/kcov.c:439 [inline] kcov_put kernel/kcov.c:435 [inline] kcov_close+0x34/0x60 kernel/kcov.c:535 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x14d/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xafb/0x2c30 kernel/exit.c:953 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 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] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1b2858effc Code: Unable to access opcode bytes at 0x7f1b2858efd2. RSP: 002b:00007ffe53a6fa00 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: 000000000000002c RBX: 00007f1b292d4620 RCX: 00007f1b2858effc RDX: 000000000000002c RSI: 00007f1b292d4670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffe53a6fa54 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f1b292d4670 R15: 0000000000000000