INFO: task syz-executor.2:18472 blocked for more than 140 seconds. Not tainted 4.14.101+ #14 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28528 18472 10824 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3495 schedule_timeout+0x736/0xe80 kernel/time/timer.c:1721 io_schedule_timeout+0x26/0x80 kernel/sched/core.c:5090 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common_io.constprop.0+0x274/0x3b0 kernel/sched/completion.c:129 submit_bio_wait+0x107/0x170 block/bio.c:954 blkdev_issue_zeroout+0x217/0x4c0 block/blk-lib.c:408 blkdev_fallocate+0x297/0x3b0 fs/block_dev.c:2017 vfs_fallocate+0x348/0x790 fs/open.c:328 SYSC_fallocate fs/open.c:351 [inline] SyS_fallocate+0x4a/0x80 fs/open.c:345 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541 2 locks held by getty/1755: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:275 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.0/14541: #0: (&sig->cred_guard_mutex){+.+.}, at: [] prepare_bprm_creds+0x51/0x110 fs/exec.c:1389 1 lock held by syz-executor.0/14563: #0: (&sig->cred_guard_mutex){+.+.}, at: [] prepare_bprm_creds+0x51/0x110 fs/exec.c:1389 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.101+ #14 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9902 Comm: loop2 Not tainted 4.14.101+ #14 task: ffff88817d635e00 task.stack: ffff8881c9378000 RIP: 0010:native_apic_mem_write+0x8/0x10 arch/x86/include/asm/apic.h:100 RSP: 0018:ffff8881d7607fc0 EFLAGS: 00000046 RAX: ffffffffa9a9aa90 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 1ffffffff579852e RSI: 0000000000000000 RDI: 00000000000000b0 RBP: ffffffffabcc2880 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881d7600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000047007d CR3: 00000001f1426003 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: apic_eoi arch/x86/include/asm/apic.h:400 [inline] ack_APIC_irq arch/x86/include/asm/apic.h:444 [inline] entering_ack_irq arch/x86/include/asm/apic.h:636 [inline] smp_apic_timer_interrupt+0x7a/0x620 arch/x86/kernel/apic/apic.c:1060 apic_timer_interrupt+0x84/0x90 arch/x86/entry/entry_64.S:787 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:778 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x59/0x70 kernel/locking/spinlock.c:192 RSP: 0018:ffff8881c937f798 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000007 RBX: 0000000000000202 RCX: 1ffff1102fac6cca RDX: 0000000000000000 RSI: ffff88817d636658 RDI: 0000000000000202 RBP: ffffffffad438458 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000202 R13: 0000000000000171 R14: 0000000000000000 R15: dffffc0000000000 spin_unlock_irqrestore include/linux/spinlock.h:372 [inline] avc_reclaim_node security/selinux/avc.c:539 [inline] avc_alloc_node security/selinux/avc.c:557 [inline] avc_alloc_node+0x28d/0x3c0 security/selinux/avc.c:545 avc_insert security/selinux/avc.c:668 [inline] avc_compute_av+0x17c/0x550 security/selinux/avc.c:974 Code: 83 3d ac ba da 02 01 77 02 5d c3 89 ef 5d e9 71 e7 fe ff 48 c7 c7 20 65 84 ac e8 84 e6 48 00 eb df 66 90 89 ff 89 b7 00 d0 5f ff 0f 1f 80 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 53 89 fb