INFO: task syz.1.2483:15847 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.2483 state:D stack:25504 pid:15847 tgid:15844 ppid:5868 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1919 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ba4d8eec9 RSP: 002b:00007f4ba5c9b038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f4ba4fe6090 RCX: 00007f4ba4d8eec9 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 000000000000000b RBP: 00007f4ba4e11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4ba4fe6128 R14: 00007f4ba4fe6090 R15: 00007fff98811938 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:6/3149: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000b787bc0 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000b787bc0 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff8880b8633cc8 (krc.lock){..-.}-{2:2}, at: kvfree_rcu_bulk+0x103/0x1f0 mm/slab_common.c:1528 2 locks held by getty/5622: #0: ffff88814d32d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz.3.1821/13253: #0: ffffffff8f5a08d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e418b48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1919 2 locks held by syz.1.2483/15847: #0: ffffffff8f5a08d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e418b48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1919 2 locks held by syz.5.2598/16291: #0: ffffffff8f5a08d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e418b48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1919 2 locks held by syz.4.2663/16561: #0: ffffffff8f5a08d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e418b48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1919 2 locks held by syz.2.2997/17903: #0: ffffffff8f5a08d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e418b48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1919 2 locks held by syz.0.3388/19392: #0: ffffffff8f5a08d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e418b48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1919 1 lock held by syz.9.3581/20145: 2 locks held by syz.8.3593/20195: #0: ffffffff8f52df10 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:566 #1: ffffffff8f53adc8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160 5 locks held by syz.7.3595/20209: #0: ffffffff8f52df10 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:566 #1: ffffffff8f28d450 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x19a/0x270 drivers/infiniband/core/device.c:1215 #2: ffffffff8f28d610 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x1d2/0x270 drivers/infiniband/core/device.c:1220 #3: ffff888033074f98 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xee/0x5c0 drivers/infiniband/core/device.c:979 #4: ffffffff8f53adc8 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x151/0x7b0 drivers/infiniband/core/verbs.c:1995 5 locks held by syz.6.3596/20208: #0: ffffffff8f5a08d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffff888076ac60e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #1: ffff888076ac60e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #1: ffff888076ac60e8 (&dev->mutex){....}-{4:4}, at: devlink_get_from_attrs_lock+0x240/0x3a0 net/devlink/netlink.c:198 #2: ffff888076ac7250 (&devlink->lock_key#13){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #2: ffff888076ac7250 (&devlink->lock_key#13){+.+.}-{4:4}, at: devlink_get_from_attrs_lock+0x24f/0x3a0 net/devlink/netlink.c:198 #3: ffffffff8f53adc8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xe5/0x670 drivers/net/netdevsim/netdev.c:1135 #4: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #4: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 20145 Comm: syz.9.3581 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x5d/0x70 kernel/kcov.c:235 Code: 18 16 00 00 83 fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 8d 7e 01 8b 89 1c 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 fe 0c b7 09 cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 RSP: 0018:ffffc9000b1af5f8 EFLAGS: 00000246 RAX: ffffffff89603361 RBX: 1ffff92001635ec4 RCX: 0000000000080000 RDX: ffffc900106b8000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc9000b1af6d0 R08: ffffc9000b1af79f R09: 0000000000000000 R10: ffffc9000b1af780 R11: fffff52001635ef4 R12: ffff888074d98280 R13: dffffc0000000000 R14: ffffc9000b1afce0 R15: ffff888057f8e000 FS: 00007f93b14936c0(0000) GS:ffff888125d39000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000fd7030 CR3: 000000009b24a000 CR4: 00000000003526f0 Call Trace: scm_recv_unix+0x81/0x360 net/core/scm.c:544 __unix_dgram_recvmsg+0x9ec/0xd60 net/unix/af_unix.c:2680 sock_recvmsg_nosec+0x183/0x1c0 net/socket.c:1065 ____sys_recvmsg+0x3aa/0x460 net/socket.c:2832 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2876 do_recvmmsg+0x307/0x770 net/socket.c:2971 __sys_recvmmsg net/socket.c:3045 [inline] __do_sys_recvmmsg net/socket.c:3068 [inline] __se_sys_recvmmsg net/socket.c:3061 [inline] __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3061 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f93b058eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f93b1493038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f93b07e5fa0 RCX: 00007f93b058eec9 RDX: 03ffffffffffff2e RSI: 0000200000000c00 RDI: 0000000000000004 RBP: 00007f93b0611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 00001000400000de R11: 0000000000000246 R12: 0000000000000000 R13: 00007f93b07e6038 R14: 00007f93b07e5fa0 R15: 00007ffe01f2cc88