INFO: task syz.3.689:8849 blocked for more than 143 seconds. Not tainted 6.15.0-rc7-syzkaller-00014-gd608703fcdd9 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.689 state:D stack:27000 pid:8849 tgid:8843 ppid:5833 task_flags:0x400140 flags:0x00004004 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_rpc_status_get_dumpit+0xb0/0x11a0 fs/nfsd/nfsctl.c:1516 genl_dumpit+0x122/0x230 net/netlink/genetlink.c:1027 netlink_dump+0x53e/0xd00 net/netlink/af_netlink.c:2309 __netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2424 genl_family_rcv_msg_dumpit+0x1e2/0x2e0 net/netlink/genetlink.c:1076 genl_family_rcv_msg net/netlink/genetlink.c:1192 [inline] genl_rcv_msg+0x46e/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x16d/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/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7812d8e969 RSP: 002b:00007f7810bf6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f7812fb6080 RCX: 00007f7812d8e969 RDX: 0000000000048084 RSI: 0000200000000140 RDI: 0000000000000009 RBP: 00007f7812e10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7812fb6080 R15: 00007ffd8a20b298 Showing all locks held in the system: 2 locks held by ksoftirqd/0/15: 1 lock held by khungtaskd/31: #0: ffffffff8e3bfa80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3bfa80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e3bfa80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764 2 locks held by getty/5593: #0: ffff888035ee20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 5 locks held by kworker/u8:10/6756: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90017c27d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90114550 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffffffff9012a3e8 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x50d/0xb30 net/core/net_namespace.c:644 #4: ffffffff8e3cafb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x280/0x3c0 kernel/rcu/tree_exp.h:304 2 locks held by kworker/u8:15/7392: #0: ffff8880b8539f18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:605 #1: ffffc90018487d18 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 2 locks held by syz.2.484/7921: #0: ffffffff901cc510 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xdd/0x1a40 fs/nfsd/nfsctl.c:1923 2 locks held by syz-executor/8155: #0: ffff8880604840e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880604840e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880604840e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff8880604840e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 3 locks held by syz.3.689/8849: #0: ffffffff901cc510 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffff8880626266d0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0x150/0x990 net/netlink/af_netlink.c:2388 #2: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xb0/0x11a0 fs/nfsd/nfsctl.c:1516 2 locks held by syz-executor/9033: #0: ffff8880237da0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880237da0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880237da0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff8880237da0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/9820: #0: ffff8880365220e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880365220e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880365220e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff8880365220e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 5 locks held by kworker/u8:38/10347: 3 locks held by syz.7.1022/10449: #0: ffffffff901cc510 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffff88806302c6d0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0x150/0x990 net/netlink/af_netlink.c:2388 #2: ffffffff8e7ceea8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xb0/0x11a0 fs/nfsd/nfsctl.c:1516 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-syzkaller-00014-gd608703fcdd9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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+0x48/0x80 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: 10347 Comm: kworker/u8:38 Not tainted 6.15.0-rc7-syzkaller-00014-gd608703fcdd9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:kmalloc_reserve+0xf2/0x2c0 net/core/skbuff.c:602 Code: e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 27 01 00 00 89 5d 00 48 8b 4c 24 38 44 89 fe 44 89 f2 48 89 df e8 51 31 d7 f8 49 89 c7 <48> 85 c0 0f 84 12 01 00 00 31 ed e8 8e f9 7c f8 4d 85 e4 74 30 e8 RSP: 0018:ffffc90003a4faa8 EFLAGS: 00000246 RAX: ffff88803fd46000 RBX: 0000000000001000 RCX: 0000000000002000 RDX: 0000000000000000 RSI: ffffffff8bf48be0 RDI: ffffffff8dce7d20 RBP: ffffc90003a4fb30 R08: 0000000000082820 R09: 00000000ffffffff R10: 0000000000000004 R11: 0000000000002bb0 R12: ffffc90003a4fb20 R13: 0000000000000820 R14: 00000000ffffffff R15: ffff88803fd46000 FS: 0000000000000000(0000) GS:ffff8881249e7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b302d9ff8 CR3: 000000007bc04000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __alloc_skb+0x166/0x380 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1340 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x2b1/0xcf0 drivers/net/netdevsim/dev.c:851 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245