INFO: task syz.2.3212:18720 blocked for more than 143 seconds. Not tainted 6.14.0-rc6-syzkaller-00244-g31d7109a19f6 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.3212 state:D stack:25296 pid:18720 tgid:18707 ppid:10163 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3e1/0x600 kernel/sched/completion.c:116 __flush_workqueue+0x3dc/0x1260 kernel/workqueue.c:4000 nbd_start_device_ioctl drivers/block/nbd.c:1541 [inline] __nbd_ioctl drivers/block/nbd.c:1602 [inline] nbd_ioctl+0x308/0xd60 drivers/block/nbd.c:1642 blkdev_ioctl+0x276/0x6d0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb58c58d169 RSP: 002b:00007fb58a3f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb58c7a6080 RCX: 00007fb58c58d169 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 00007fb58c60e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb58c7a6080 R15: 00007ffc2be8dfd8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 2 locks held by getty/5570: #0: ffff88803235b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 2 locks held by kworker/u9:2/5819: #0: ffff888025c4a148 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc90003b6fd18 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 2 locks held by kworker/u8:9/6244: 4 locks held by kworker/u8:26/15193: #0: ffff88801beeb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc9000432fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8fee2710 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xca/0xb30 net/core/net_namespace.c:606 #3: ffffffff8fef8428 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x8c/0xae0 net/core/dev.c:12420 3 locks held by kworker/0:2/16526: #0: ffff88801b078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc9000464fd18 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8e1c85b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:334 3 locks held by kworker/u8:18/18656: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc900044e7d18 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8fef8428 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:285 3 locks held by kworker/u8:0/19015: 1 lock held by syz.1.3335/19362: #0: ffffffff8e1c85b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:334 6 locks held by syz-executor/20295: #0: ffffffff8fee2710 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:512 #1: ffffffff8fb44730 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x234/0x530 drivers/infiniband/core/device.c:1169 #2: ffffffff8fb444b0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x2a7/0x530 drivers/infiniband/core/device.c:1174 #3: ffff8880307a4f48 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0x112/0x720 drivers/infiniband/core/device.c:933 #4: ffff8880307a5240 (&rxe->usdev_lock){+.+.}-{4:4}, at: rxe_query_port+0xf1/0x330 drivers/infiniband/sw/rxe/rxe_verbs.c:61 #5: ffffffff8fef8428 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x118/0xb50 drivers/infiniband/core/verbs.c:1995 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00244-g31d7109a19f6 #0 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+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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0xf62/0x12b0 kernel/hung_task.c:399 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 20301 Comm: syz.0.3573 Not tainted 6.14.0-rc6-syzkaller-00244-g31d7109a19f6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__lock_acquire+0x263/0x3c40 kernel/locking/lockdep.c:5154 Code: 41 0f b7 56 20 8b 7c 24 20 81 e2 ff 1f 00 00 39 fa 75 0c 48 83 7c 24 10 00 0f 85 36 0d 00 00 48 8b 44 24 28 44 0f b7 74 24 20 <49> 01 c7 49 8d 47 20 66 41 81 e6 ff 1f 48 89 c2 48 89 44 24 38 48 RSP: 0018:ffffc9000568f700 EFLAGS: 00000046 RAX: ffff888068280af0 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffff888068280af0 RDI: ffffffff8e1bd148 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8e1bd140 R13: ffff888068280000 R14: 0000000000000021 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5d9c8d7d60 CR3: 000000000df80000 CR4: 00000000003526f0 DR0: 0000000000000007 DR1: 0000000000000002 DR2: 0000000000000008 DR3: 1000000100000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3a/0x310 mm/page_ext.c:525 __reset_page_owner+0x32/0x400 mm/page_owner.c:290 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660 vfree+0x174/0x950 mm/vmalloc.c:3383 kcov_put kernel/kcov.c:439 [inline] kcov_put+0x2a/0x40 kernel/kcov.c:435 kcov_close+0xd/0x20 kernel/kcov.c:535 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xad8/0x2d70 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x24ed/0x26c0 kernel/signal.c:3036 arch_do_signal_or_restart+0x90/0x7e0 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+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff34b78d1a3 Code: Unable to access opcode bytes at 0x7ff34b78d179. RSP: 002b:00007fff3afe6058 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: 00007ff34c5b1000 RBX: 00007ff349df76c0 RCX: 00007ff34b78d1a3 RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000020022 R11: 0000000000000246 R12: 00007fff3afe61b0 R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000