INFO: task syz-executor4:30380 blocked for more than 120 seconds. Not tainted 4.15.0-rc9+ #277 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D25648 30380 3716 0x00000004 Call Trace: context_switch kernel/sched/core.c:2799 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3375 schedule+0xf5/0x430 kernel/sched/core.c:3434 blk_mq_freeze_queue_wait+0x1bb/0x400 block/blk-mq.c:137 blk_freeze_queue+0x4a/0x80 block/blk-mq.c:166 blk_mq_freeze_queue+0x15/0x20 block/blk-mq.c:175 loop_set_status+0x1a2/0xf60 drivers/block/loop.c:1097 loop_set_status64+0x9d/0x110 drivers/block/loop.c:1271 lo_ioctl+0xd86/0x1b70 drivers/block/loop.c:1381 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x1759/0x1e00 block/ioctl.c:601 block_ioctl+0xde/0x120 fs/block_dev.c:1860 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x452f19 RSP: 002b:00007f14cafb3c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452f19 RDX: 0000000020ba0000 RSI: 0000000000004c04 RDI: 0000000000000013 RBP: 000000000000061c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f8340 R13: 00000000ffffffff R14: 00007f14cafb46d4 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/746: #0: (rcu_read_lock){....}, at: [<00000000ee37c70c>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000ee37c70c>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<0000000003f8e0ef>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4464 2 locks held by getty/3633: #0: (&tty->ldisc_sem){++++}, at: [<00000000a6e5283f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070c30d64>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3634: #0: (&tty->ldisc_sem){++++}, at: [<00000000a6e5283f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070c30d64>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3635: #0: (&tty->ldisc_sem){++++}, at: [<00000000a6e5283f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070c30d64>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3636: #0: (&tty->ldisc_sem){++++}, at: [<00000000a6e5283f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070c30d64>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3637: #0: (&tty->ldisc_sem){++++}, at: [<00000000a6e5283f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070c30d64>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3638: #0: (&tty->ldisc_sem){++++}, at: [<00000000a6e5283f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070c30d64>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3639: #0: (&tty->ldisc_sem){++++}, at: [<00000000a6e5283f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070c30d64>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 1 lock held by syz-executor4/30380: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000366b50c5>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 1 lock held by syz-executor4/30385: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000366b50c5>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 1 lock held by blkid/30387: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000366b50c5>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 746 Comm: khungtaskd Not tainted 4.15.0-rc9+ #277 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:541 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3511 Comm: rsyslogd Not tainted 4.15.0-rc9+ #277 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x66c/0x3e00 kernel/locking/lockdep.c:3387 RSP: 0018:ffff8801c0b5f4d0 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff8801bfe7c9c8 RCX: 1ffffffff0f454d2 RDX: ffff8801bfe7c9e8 RSI: 1ffff10037fcf93d RDI: ffffffff87a2a690 RBP: ffff8801c0b5f860 R08: 1ffff1003816be77 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000080 R12: 000000000000005b R13: ffff8801bfe7c9ea R14: 0000000000000002 R15: ffff8801bfe7c100 FS: 00007f431b2ef700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000fda800 CR3: 00000001d1d4f004 CR4: 00000000001606f0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 __raw_spin_trylock include/linux/spinlock_api_smp.h:90 [inline] _raw_spin_trylock+0x43/0x50 kernel/locking/spinlock.c:128 avc_reclaim_node security/selinux/avc.c:524 [inline] avc_alloc_node+0x17b/0x4d0 security/selinux/avc.c:557 avc_insert security/selinux/avc.c:668 [inline] avc_compute_av+0x22a/0x710 security/selinux/avc.c:974 avc_has_perm_noaudit security/selinux/avc.c:1110 [inline] avc_has_perm+0x4be/0x680 security/selinux/avc.c:1144 inode_has_perm security/selinux/hooks.c:1771 [inline] file_has_perm+0x3f5/0x5d0 security/selinux/hooks.c:1861 selinux_revalidate_file_permission security/selinux/hooks.c:3428 [inline] selinux_file_permission+0x31c/0x460 security/selinux/hooks.c:3449 security_file_permission+0x7d/0x1e0 security/security.c:864 rw_verify_area+0xde/0x2b0 fs/read_write.c:386 vfs_read+0xf2/0x350 fs/read_write.c:443 SYSC_read fs/read_write.c:573 [inline] SyS_read+0xef/0x220 fs/read_write.c:566 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x7f431dd4f1fd RSP: 002b:00007f431b2eee30 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000001fb0120 RCX: 00007f431dd4f1fd RDX: 0000000000000fff RSI: 00007f431cb235a0 RDI: 0000000000000004 RBP: 000000000065e478 R08: 0000000001fb0260 R09: 0000000004000001 R10: 0000000000000001 R11: 0000000000000293 R12: 000000000065e200 R13: 0000000000000000 R14: 0000000000000001 R15: 00007f431cb23b47 Code: 48 89 de 4c 89 ff e8 64 d3 ff ff 85 c0 0f 84 50 03 00 00 ba 08 00 00 00 48 89 de 4c 89 ff e8 4c d3 ff ff 85 c0 0f 84 38 03 00 00 <48> c7 c2 00 72 f0 87 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03