NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task syz-executor.1:12593 blocked for more than 140 seconds. Not tainted 4.19.122-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28416 12593 6544 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x896/0xf20 kernel/time/timer.c:1782 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x26a/0x3c0 kernel/sched/completion.c:136 flush_workqueue+0x40f/0x14b0 kernel/workqueue.c:2715 nbd_start_device_ioctl drivers/block/nbd.c:1262 [inline] __nbd_ioctl drivers/block/nbd.c:1333 [inline] nbd_ioctl+0x502/0xb80 drivers/block/nbd.c:1373 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0xbf7/0x1a1c block/ioctl.c:601 block_ioctl+0xe9/0x130 fs/block_dev.c:1894 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 08 48 c7 44 24 10 09 00 00 00 e8 02 a1 fa ff 48 8b 44 24 18 48 8b 4c 24 30 48 83 c1 10 48 89 0c 24 48 89 44 24 08 48 c7 44 24 <10> 58 1f 00 00 e8 dd a0 fa ff 48 8b 44 24 18 48 89 44 24 40 48 8b RSP: 002b:00007f5bdaa56c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e8e20 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000409 R14: 00000000004c6a64 R15: 00007f5bdaa576d4 Showing all locks held in the system: 1 lock held by khungtaskd/1079: #0: 00000000bdde8183 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 1 lock held by in:imklog/6127: #0: 0000000016463392 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767 2 locks held by kworker/u5:1/8041: #0: 0000000002c45186 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 0000000002c45186 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000002c45186 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000002c45186 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000002c45186 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000002c45186 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000002c45186 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x81a/0x1640 kernel/workqueue.c:2126 #1: 000000008347511b ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x84e/0x1640 kernel/workqueue.c:2130 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1079 Comm: khungtaskd Not tainted 4.19.122-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+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x962/0xe40 kernel/hung_task.c:287 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3690 Comm: systemd-journal Not tainted 4.19.122-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:unwind_next_frame+0x40b/0x18a0 arch/x86/kernel/unwind_orc.c:473 Code: 89 74 24 60 e8 36 fb ff ff 48 8b 4c 24 18 84 c0 4c 8b 44 24 20 0f 84 b3 00 00 00 0f b6 41 05 83 e0 03 3c 01 0f 84 6b 0a 00 00 <3c> 02 0f 84 0c 09 00 00 84 c0 0f 84 04 07 00 00 80 3d 44 1b 7f 08 RSP: 0018:ffff888093cef978 EFLAGS: 00000297 RAX: 0000000000000000 RBX: 1ffff1101279df37 RCX: ffffffff8a161ff8 RDX: ffff888093cefd48 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffff8a161ffc R09: 0000000000000001 R10: 0000000000024854 R11: 0000000000066071 R12: ffff888093cefa98 R13: ffff888093cefa85 R14: ffff888093cefa88 R15: ffff888093cefa50 FS: 00007f66096f38c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6606b85000 CR3: 0000000094408000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __save_stack_trace+0x7a/0xf0 arch/x86/kernel/stacktrace.c:44 save_stack+0x32/0xa0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc mm/slab.c:3397 [inline] __do_kmalloc mm/slab.c:3725 [inline] __kmalloc_track_caller+0x13d/0x770 mm/slab.c:3742 kmemdup+0x23/0x50 mm/util.c:118 kmemdup include/linux/string.h:421 [inline] selinux_cred_prepare+0x44/0xa0 security/selinux/hooks.c:3982 security_prepare_creds+0x6c/0xb0 security/security.c:1014 prepare_creds+0x32d/0x410 kernel/cred.c:282 do_faccessat+0x94/0x7a0 fs/open.c:359 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f66089af9c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe232bdbf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffe232c0b10 RCX: 00007f66089af9c7 RDX: 00007f6609420a00 RSI: 0000000000000000 RDI: 000055eef6c6e9a3 RBP: 00007ffe232bdc30 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffe232c0b10 R15: 00007ffe232be120