INFO: task syz-executor.0:6571 blocked for more than 143 seconds. Not tainted 5.7.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28120 6571 18251 0x00004004 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x937/0x1ff0 kernel/sched/core.c:4083 schedule+0xd0/0x2a0 kernel/sched/core.c:4158 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1874 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x16a/0x270 kernel/sched/completion.c:138 flush_workqueue+0x403/0x14f0 kernel/workqueue.c:2831 nbd_start_device_ioctl drivers/block/nbd.c:1322 [inline] __nbd_ioctl drivers/block/nbd.c:1397 [inline] nbd_ioctl+0x7ae/0xb7f drivers/block/nbd.c:1437 __blkdev_driver_ioctl block/ioctl.c:322 [inline] blkdev_ioctl+0x25b/0x660 block/ioctl.c:718 block_ioctl+0xf9/0x140 fs/block_dev.c:2005 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:771 __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl fs/ioctl.c:778 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: Bad RIP value. RSP: 002b:00007faa6b6d5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e91c0 RCX: 000000000045ca29 RDX: 0000000000000008 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000040e R14: 00000000004c6ccb R15: 00007faa6b6d66d4 Showing all locks held in the system: 3 locks held by kworker/u4:5/460: #0: ffff8880ae737998 (&rq->lock){-.-.}-{2:2}, at: newidle_balance+0x9be/0xdb0 kernel/sched/fair.c:10537 #1: ffffffff899bea80 (rcu_read_lock){....}-{1:2}, at: __update_idle_core+0x42/0x3e0 kernel/sched/fair.c:5994 #2: ffff8880ae727598 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x55/0x1a0 kernel/time/timer.c:936 1 lock held by khungtaskd/1144: #0: ffffffff899bea80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 1 lock held by in:imklog/6811: #0: ffff8880a665b8f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by kworker/u5:0/25337: #0: ffff88809ff90938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff88809ff90938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88809ff90938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff88809ff90938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff88809ff90938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff88809ff90938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff88809ff90938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2239 #1: ffffc900063e7dc0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1144 Comm: khungtaskd Not tainted 5.7.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4115 Comm: systemd-journal Not tainted 5.7.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:956 [inline] RIP: 0010:debug_check_no_obj_freed+0xf7/0x449 lib/debugobjects.c:998 Code: 44 24 18 80 38 00 0f 85 28 03 00 00 48 8b 44 24 10 4c 8b 38 4d 85 ff 0f 84 26 02 00 00 31 ed 4c 89 f8 48 c1 e8 03 80 3c 18 00 <0f> 85 2d 02 00 00 49 8d 7f 18 83 c5 01 4d 8b 27 48 89 f8 48 c1 e8 RSP: 0018:ffffc900016e7aa0 EFLAGS: 00000046 RAX: 1ffff110121f00f5 RBX: dffffc0000000000 RCX: ffffffff815a9099 RDX: 1ffffffff1921080 RSI: 0000000000000082 RDI: ffff888090f808d8 RBP: 0000000000000001 R08: 0000000000000004 R09: fffff520002dcf43 R10: 0000000000000003 R11: fffff520002dcf42 R12: ffff888090f807a8 R13: ffffffff8c9083f0 R14: ffff8880a6ee3048 R15: ffff888090f807a8 FS: 00007f84322078c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f842fa0e000 CR3: 0000000093a6c000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000006980 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: free_pages_prepare mm/page_alloc.c:1220 [inline] __free_pages_ok+0x252/0xe90 mm/page_alloc.c:1472 slab_destroy+0x14/0x40 mm/slab.c:1620 slabs_destroy+0x6a/0x90 mm/slab.c:1636 cache_flusharray mm/slab.c:3413 [inline] ___cache_free+0x29f/0x3a0 mm/slab.c:3457 qlink_free mm/kasan/quarantine.c:148 [inline] qlist_free_all+0x79/0x140 mm/kasan/quarantine.c:167 quarantine_reduce+0x135/0x170 mm/kasan/quarantine.c:260 __kasan_kmalloc.constprop.0+0x97/0xd0 mm/kasan/common.c:476 slab_post_alloc_hook mm/slab.h:586 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x11b/0x740 mm/slab.c:3484 getname_flags fs/namei.c:138 [inline] getname_flags+0xd2/0x5b0 fs/namei.c:128 do_sys_openat2+0x3fc/0x7d0 fs/open.c:1142 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x7f8431797840 Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 RSP: 002b:00007ffee71aec48 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffee71aef50 RCX: 00007f8431797840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 0000563c94aa5ae0 RBP: 000000000000000d R08: 00000000000001c0 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000563c94a98040 R14: 00007ffee71aef10 R15: 0000563c94aa5b30