INFO: task syz.4.3347:18802 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.3347 state:D stack:25568 pid:18802 tgid:18798 ppid:17992 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821 nfsd_nl_listener_set_doit+0x135/0x1750 fs/nfsd/nfsctl.c:1964 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2684 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738 __sys_sendmsg net/socket.c:2770 [inline] __do_sys_sendmsg net/socket.c:2775 [inline] __se_sys_sendmsg net/socket.c:2773 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ca1b9de99 RSP: 002b:00007f4ca29cb028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f4ca1e26090 RCX: 00007f4ca1b9de99 RDX: 0000000004000080 RSI: 0000200000000100 RDI: 0000000000000007 RBP: 00007f4ca1c33eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4ca1e26128 R14: 00007f4ca1e26090 R15: 00007ffe5d712be8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5376: #0: ffff8880369970a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:41/12708: 2 locks held by syz.4.3347/18799: #0: ffffffff9009d568 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ee8e5e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x135/0x1750 fs/nfsd/nfsctl.c:1964 2 locks held by syz.4.3347/18802: #0: ffffffff9009d568 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ee8e5e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x135/0x1750 fs/nfsd/nfsctl.c:1964 2 locks held by syz.3.3885/20772: #0: ffffffff9009d568 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ee8e5e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_cache_flush_doit+0xb5/0x1b0 fs/nfsd/nfsctl.c:2236 7 locks held by syz.2.4544/23190: #0: ffffffff9ab25148 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:164 [inline] #0: ffffffff9ab25148 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] #0: ffffffff9ab25148 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x33d/0xa40 drivers/infiniband/core/netlink.c:259 #1: ffffffff8fd8b828 (link_ops_rwsem){++++}-{4:4}, at: nldev_newlink+0x429/0x650 drivers/infiniband/core/nldev.c:1806 #2: ffffffff8fd7cce8 (devices_rwsem){++++}-{4:4}, at: enable_device_and_get+0xff/0x3e0 drivers/infiniband/core/device.c:1331 #3: ffffffff8fd7cea8 (rdma_nets_rwsem){++++}-{4:4}, at: add_compat_devs drivers/infiniband/core/device.c:1035 [inline] #3: ffffffff8fd7cea8 (rdma_nets_rwsem){++++}-{4:4}, at: enable_device_and_get+0x27c/0x3e0 drivers/infiniband/core/device.c:1347 #4: ffff8880795e0fe0 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650 drivers/infiniband/core/device.c:953 #5: ffff8880795e12d0 (&rxe->usdev_lock){+.+.}-{4:4}, at: rxe_query_port+0x7e/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:55 #6: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x173/0x7f0 drivers/infiniband/core/verbs.c:2051 3 locks held by syz.0.4587/23338: #0: ffffffff8f7a68e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8f7a68e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8f7a68e8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 #2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.0.4587/23340: #0: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 2 locks held by syz.0.4587/23348: #0: ffffffff90596100 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff90596100 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff90596100 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 2 locks held by syz.1.4588/23339: #0: ffffffff90030600 (bpf_dispatcher_xdp.mutex){+.+.}-{4:4}, at: bpf_dispatcher_change_prog+0xc2/0xf20 kernel/bpf/dispatcher.c:146 #1: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.6.4589/23341: #0: ffff8880768bb040 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff8880768bb040 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:709 [inline] #0: ffff8880768bb040 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220 net/socket.c:1501 2 locks held by syz.6.4589/23343: #0: ffffffff9057bec0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff9057bec0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff9057bec0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 1 lock held by syz.6.4589/23344: #0: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: __dev_ethtool net/ethtool/ioctl.c:3626 [inline] #0: ffffffff9002cd00 (rtnl_mutex){+.+.}-{4:4}, at: dev_ethtool+0x3a0/0x29c0 net/ethtool/ioctl.c:3669 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 5610 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 RIP: 0010:vfs_read+0x168/0xa80 fs/read_write.c:566 Code: df 0f 82 fb 07 00 00 4d 39 f7 0f 87 f2 07 00 00 31 ff 4c 8b 7c 24 18 4c 89 fe 48 8b 54 24 20 4c 89 e9 e8 1b ef ff ff 41 89 c6 <31> ff 89 c6 e8 af 45 80 ff 45 85 f6 74 17 e8 65 41 80 ff 49 63 c6 RSP: 0018:ffffc90003a3fca0 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 00007fff3f9592dc RCX: ffff88807b30be00 RDX: 0000000000000000 RSI: 0000000004000000 RDI: 0000000000000000 RBP: ffffc90003a3fe10 R08: ffffffff848fbfbb R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: 1ffff92000747fa0 R13: 0000000000000004 R14: 0000000000000000 R15: ffff888074d41500 FS: 000055557d91c540(0000) GS:ffff888124f54000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc72f7ef4b8 CR3: 0000000074d42000 CR4: 00000000003526f0 Call Trace: ksys_read+0x150/0x270 fs/read_write.c:716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fee21d59017 Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fff3f959280 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055557d91c540 RCX: 00007fee21d59017 RDX: 0000000000000004 RSI: 00007fff3f9592dc RDI: 0000000000000003 RBP: 00007fff3f959780 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 R13: 00007fff3f9592dc R14: 00007fff3f959370 R15: 0000000000000000