INFO: task syz.1.3986:20467 blocked for more than 143 seconds. Not tainted 6.15.0-rc4-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3986 state:D stack:26264 pid:20467 tgid:20465 ppid:16575 task_flags:0x400548 flags:0x00024002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148 io_wq_exit_workers io_uring/io-wq.c:1294 [inline] io_wq_put_and_exit+0x31b/0x690 io_uring/io-wq.c:1322 io_uring_clean_tctx+0x11f/0x1a0 io_uring/tctx.c:205 io_uring_cancel_generic+0x68f/0x730 io_uring/io_uring.c:3216 io_uring_files_cancel include/linux/io_uring.h:19 [inline] do_exit+0x56a/0x2550 kernel/exit.c:909 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x125e/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0x95/0x780 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x8b/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0caa18e969 RSP: 002b:00007f0caafc8038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: 0000000000010106 RBX: 00007f0caa3b6080 RCX: 00007f0caa18e969 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000007 RBP: 00007f0caa210ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0caa3b6080 R15: 00007ffeaebb94f8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 5 locks held by kworker/u8:3/53: #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000be7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000be7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2d49d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608 #3: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12524 #4: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #4: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998 2 locks held by getty/5579: #0: ffff8880351e20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5811: #0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:613 3 locks held by kworker/u8:14/10136: #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc900046efc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900046efc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by iou-wrk-20467/20468: #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:289 [inline] #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_provide_buffers+0x7a1/0xa70 io_uring/kbuf.c:562 1 lock held by iou-wrk-20467/20469: #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:289 [inline] #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_provide_buffers+0x7a1/0xa70 io_uring/kbuf.c:562 1 lock held by iou-wrk-20467/20470: #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:289 [inline] #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_provide_buffers+0x7a1/0xa70 io_uring/kbuf.c:562 1 lock held by iou-wrk-20467/20471: #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:289 [inline] #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_provide_buffers+0x7a1/0xa70 io_uring/kbuf.c:562 1 lock held by iou-wrk-20467/20472: #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:289 [inline] #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_provide_buffers+0x7a1/0xa70 io_uring/kbuf.c:562 1 lock held by iou-wrk-20467/20473: #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:289 [inline] #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_provide_buffers+0x7a1/0xa70 io_uring/kbuf.c:562 1 lock held by iou-wrk-20467/20474: 1 lock held by iou-wrk-20467/20475: #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:289 [inline] #0: ffff8880775200a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_provide_buffers+0x7a1/0xa70 io_uring/kbuf.c:562 7 locks held by syz-executor/21744: #0: ffff888035250420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff888035250420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680 #1: ffff88814d0a6888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffff8881453770f8 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8eb820e8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:166 #4: ffff888028a630e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #4: ffff888028a630e8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1004 #5: ffff888028a61250 (&devlink->lock_key#26){+.+.}-{4:4}, at: nsim_drv_probe+0xc1/0xb70 drivers/net/netdevsim/dev.c:1537 #6: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:948 [inline] #6: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: nsim_create+0x7df/0xef0 drivers/net/netdevsim/netdev.c:1028 4 locks held by syz-executor/21766: #0: ffff888035250420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff888035250420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680 #1: ffff888146776488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffff8881453771e8 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8eb820e8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:216 1 lock held by syz.3.4278/21897: #0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6961 1 lock held by syz.7.4280/21905: #0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6961 1 lock held by syz.0.4283/21914: #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5811 Comm: syz-executor Not tainted 6.15.0-rc4-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:lockdep_hardirqs_on+0x64/0x150 kernel/locking/lockdep.c:4461 Code: 75 51 65 8b 05 1d 84 23 07 85 c0 75 7b 65 8b 05 ca 80 23 07 85 c0 75 70 83 3d 67 6e 2e 0e 00 75 32 48 c7 04 24 00 00 00 00 9c <8f> 04 24 f7 04 24 00 02 00 00 75 6e 83 3d 49 6e 2e 0e 00 75 14 48 RSP: 0018:ffffc90003f7f890 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88802f9b8000 RCX: ae9fcbcb0373df00 RDX: 0000000000000006 RSI: ffffffff8d91f7da RDI: ffffffff8185b63d RBP: ffffc90003f7f950 R08: ffffffff8f7d9f77 R09: 1ffffffff1efb3ee R10: dffffc0000000000 R11: fffffbfff1efb3ef R12: ffffffff89c5f15a R13: ffff888023fda640 R14: dffffc0000000000 R15: 1ffff920007eff18 FS: 0000555556f32500(0000) GS:ffff888126202000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556d265c8 CR3: 00000000333e4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __local_bh_enable_ip+0x12d/0x1c0 kernel/softirq.c:412 lock_sock include/net/sock.h:1651 [inline] tcp_recvmsg+0x1fa/0x810 net/ipv4/tcp.c:2877 inet_recvmsg+0x147/0x250 net/ipv4/af_inet.c:883 sock_recvmsg_nosec net/socket.c:1017 [inline] sock_recvmsg+0x1a8/0x270 net/socket.c:1039 sock_read_iter+0x231/0x2f0 net/socket.c:1109 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x4cd/0x980 fs/read_write.c:570 ksys_read+0x145/0x250 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff8ea98d33d Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b5 e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d 01 72 1f 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec RSP: 002b:00007fff3af8d5e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff8ea98d33d RDX: 0000000000000004 RSI: 00007fff3af8d5fc RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000015ca7136 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff3af8da10 R13: 0000000000000004 R14: 00007fff3af8d5fc R15: 00007fff3af8d690