INFO: task syz.1.3652:22070 blocked for more than 143 seconds. Tainted: G U 6.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3652 state:D stack:27184 pid:22070 tgid:22069 ppid:15085 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: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: 0033:0x7f67daf8d169 RSP: 002b:00007f67dbed3038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f67db1a5fa0 RCX: 00007f67daf8d169 RDX: 0000000000000810 RSI: 0000400000002640 RDI: 0000000000000009 RBP: 00007f67db00e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f67db1a5fa0 R15: 00007ffd8ef63af8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 4 locks held by syz-executor/20067: 2 locks held by syz.2.3520/21367: #0: ffffffff8ff99c70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5bfe28 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629 2 locks held by getty/21548: #0: ffff888031b840a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000a38d2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:10/21775: #0: ffff8881476a8948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc9000c867d18 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 2 locks held by syz.1.3652/22070: #0: ffffffff8ff99c70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5bfe28 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U 6.14.0-rc4-syzkaller #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: 21771 Comm: kworker/u8:2 Tainted: G U 6.14.0-rc4-syzkaller #0 Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:469 [inline] RIP: 0010:lock_acquire.part.0+0x122/0x380 kernel/locking/lockdep.c:5853 Code: 6a 00 41 0f 94 c1 6a 00 45 0f b6 c9 ff b4 24 f8 00 00 00 41 57 44 8b 44 24 2c 8b 4c 24 28 e8 45 ae ff ff 48 c7 c7 80 ef 6c 8b <48> 83 c4 28 e8 35 7c be 09 b8 ff ff ff ff 65 0f c1 05 e0 da 6b 7e RSP: 0018:ffffc9000c8179e8 EFLAGS: 00000082 RAX: 0000000000000001 RBX: 1ffff92001902f43 RCX: 0000000012fbaf26 RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffffffff8b6cef80 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff2dd7d98 R10: ffffffff96ebecc7 R11: 0000000000000003 R12: 0000000000000000 R13: ffffffff8e1bcc80 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc4cbd78ab8 CR3: 000000002ffc8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:754 [inline] batadv_iv_ogm_schedule_buff+0x5ac/0x14d0 net/batman-adv/bat_iv_ogm.c:825 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:868 [inline] batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:861 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x31e/0x8d0 net/batman-adv/bat_iv_ogm.c:1712 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 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