INFO: task syz.2.521:7989 blocked for more than 143 seconds. Not tainted 6.15.0-rc2-syzkaller-00577-g8066e388be48 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.521 state:D stack:24416 pid:7989 tgid:7987 ppid:5834 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 __lock_sock+0x1cf/0x340 net/core/sock.c:3135 lock_sock_nested+0x9e/0x100 net/core/sock.c:3703 lock_sock include/net/sock.h:1651 [inline] sk_stream_wait_memory+0x93e/0xfa0 net/core/stream.c:145 mptcp_sendmsg+0x107e/0x1a20 net/mptcp/protocol.c:1823 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:727 sock_write_iter+0x2d9/0x3f0 net/socket.c:1131 do_iter_readv_writev+0x71f/0x9d0 fs/read_write.c:-1 vfs_writev+0x38d/0xbc0 fs/read_write.c:1055 do_writev+0x1b8/0x360 fs/read_write.c:1101 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f60c5f8e169 RSP: 002b:00007f60c6d79038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f60c61b6080 RCX: 00007f60c5f8e169 RDX: 0000000000000001 RSI: 0000200000000200 RDI: 0000000000000005 RBP: 00007f60c6010a68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f60c61b6080 R15: 00007fff0abfef58 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764 2 locks held by getty/5594: #0: ffff888031cba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900030062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222 4 locks held by kworker/0:15/6165: 2 locks held by kworker/u8:26/6913: #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000303fc60 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000303fc60 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 1 lock held by syz.2.521/7989: #0: ffff888030ab3bd8 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff888030ab3bd8 (sk_lock-AF_INET){+.+.}-{0:0}, at: sk_stream_wait_memory+0x93e/0xfa0 net/core/stream.c:145 2 locks held by syz.0.643/8485: #0: ffffffff900f1dd0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:568 #1: ffffffff8ed43300 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3774 4 locks held by syz.3.647/8499: #0: ffffffff901635d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffff88805c96c0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #1: ffff88805c96c0e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #1: ffff88805c96c0e8 (&dev->mutex){....}-{4:4}, at: devlink_get_from_attrs_lock+0x266/0x410 net/devlink/netlink.c:198 #2: ffff88805c96d250 (&devlink->lock_key#2){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #2: ffff88805c96d250 (&devlink->lock_key#2){+.+.}-{4:4}, at: devlink_get_from_attrs_lock+0x275/0x410 net/devlink/netlink.c:198 #3: ffffffff8ed43300 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3774 1 lock held by syz.5.678/8597: #0: ffffffff8ed43300 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3774 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc2-syzkaller-00577-g8066e388be48 #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+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 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+0x1058/0x10a0 kernel/hung_task.c:437 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/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: 6165 Comm: kworker/0:15 Not tainted 6.15.0-rc2-syzkaller-00577-g8066e388be48 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events mptcp_worker RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:-1 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3822 [inline] RIP: 0010:validate_chain+0xa7/0x24e0 kernel/locking/lockdep.c:3877 Code: c6 2c 87 55 8e e8 59 5d e3 ff 90 0f 0b 90 90 90 48 bd eb 83 b5 80 46 86 c8 61 48 0f af eb 48 c1 ed 2d 48 8b 04 ed f0 e6 2a 94 <48> 85 c0 74 1c 48 83 c0 f8 74 16 48 8b 48 18 48 39 d9 0f 84 cf 01 RSP: 0018:ffffc900000069a0 EFLAGS: 00000002 RAX: ffffffff94830d68 RBX: 22f0d2b1a9bc4ef4 RCX: 0000000000040000 RDX: 0000000000000000 RSI: ffff88802724c808 RDI: ffff88802724bc00 RBP: 000000000001c676 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff93675020 R14: ffff88802724bc00 R15: ffff88802724c808 FS: 0000000000000000(0000) GS:ffff888124fab000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffdfa50000 CR3: 000000007f248000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __dev_xmit_skb net/core/dev.c:4106 [inline] __dev_queue_xmit+0xe04/0x3f60 net/core/dev.c:4647 dev_queue_xmit include/linux/netdevice.h:3349 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip_finish_output2+0xcd2/0x12e0 net/ipv4/ip_output.c:235 synproxy_send_client_synack+0x8ea/0xf70 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x3cc/0x610 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x36a/0xa90 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x4b2/0x1db0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x41f/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc8/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29b/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a0/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5941 [inline] __netif_receive_skb+0x2c9/0x670 net/core/dev.c:6054 process_backlog+0x664/0x15c0 net/core/dev.c:6406 __napi_poll+0xcb/0x480 net/core/dev.c:7378 napi_poll net/core/dev.c:7442 [inline] net_rx_action+0x89d/0x1240 net/core/dev.c:7564 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579 do_softirq+0x11f/0x1e0 kernel/softirq.c:480 __local_bh_enable_ip+0x1be/0x200 kernel/softirq.c:407 spin_unlock_bh include/linux/spinlock.h:396 [inline] mptcp_check_and_set_pending net/mptcp/protocol.c:1438 [inline] __mptcp_retrans+0xaf3/0xe90 net/mptcp/protocol.c:2615 mptcp_release_cb+0x709/0xa70 net/mptcp/protocol.c:3373 release_sock+0x1aa/0x1f0 net/core/sock.c:3716 mptcp_worker+0xcca/0x1440 net/mptcp/protocol.c:2711 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245