random: cc1: uninitialized urandom read (8 bytes read) audit: type=1400 audit(1552161453.819:9): avc: denied { map } for pid=1946 comm="syz-execprog" path="/root/syzkaller-shm673589165" dev="sda1" ino=16482 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:file_t:s0 tclass=file permissive=1 INFO: task syz-executor.2:1962 blocked for more than 140 seconds. Not tainted 4.14.105+ #29 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D25144 1962 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_ioctl+0x83/0x1970 drivers/block/loop.c:1405 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x4d9/0x1810 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.4:1970 blocked for more than 140 seconds. Not tainted 4.14.105+ #29 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25640 1970 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x41b/0xd60 fs/open.c:764 vfs_open+0x105/0x230 fs/open.c:878 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.5:1972 blocked for more than 140 seconds. Not tainted 4.14.105+ #29 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D25640 1972 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x41b/0xd60 fs/open.c:764 vfs_open+0x105/0x230 fs/open.c:878 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.0:1975 blocked for more than 140 seconds. Not tainted 4.14.105+ #29 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D25640 1975 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x41b/0xd60 fs/open.c:764 vfs_open+0x105/0x230 fs/open.c:878 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.1:1978 blocked for more than 140 seconds. Not tainted 4.14.105+ #29 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25560 1978 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x41b/0xd60 fs/open.c:764 vfs_open+0x105/0x230 fs/open.c:878 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.3:3042 blocked for more than 140 seconds. Not tainted 4.14.105+ #29 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28688 3042 1968 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions+0x72/0x80 drivers/block/loop.c:615 loop_set_status+0xbff/0x11f0 drivers/block/loop.c:1184 INFO: task blkid:3043 blocked for more than 140 seconds. Not tainted 4.14.105+ #29 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28664 3043 2920 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __lo_release drivers/block/loop.c:1644 [inline] lo_release+0x78/0x190 drivers/block/loop.c:1668 __blkdev_put+0x518/0x6d0 fs/block_dev.c:1791 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25e/0x700 fs/file_table.c:210 task_work_run+0x118/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x13b/0x160 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:267 [inline] do_syscall_64+0x372/0x4b0 arch/x86/entry/common.c:294 INFO: task blkid:3045 blocked for more than 140 seconds. Not tainted 4.14.105+ #29 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D29344 3045 308 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_ioctl+0x83/0x1970 drivers/block/loop.c:1405 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x4d9/0x1810 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task blkid:3048 blocked for more than 140 seconds. Not tainted 4.14.105+ #29 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D27232 3048 2926 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x41b/0xd60 fs/open.c:764 vfs_open+0x105/0x230 fs/open.c:878 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task blkid:3052 blocked for more than 140 seconds. Not tainted 4.14.105+ #29 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D29264 3052 2919 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x41b/0xd60 fs/open.c:764 vfs_open+0x105/0x230 fs/open.c:878 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1071 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/1757: #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.2/1962: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1405 2 locks held by syz-executor.4/1970: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.5/1972: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.0/1975: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.1/1978: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.3/3042: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 3 locks held by blkid/3043: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [] lo_release+0x19/0x190 drivers/block/loop.c:1667 #2: (loop_ctl_mutex#2){+.+.}, at: [] __lo_release drivers/block/loop.c:1644 [inline] #2: (loop_ctl_mutex#2){+.+.}, at: [] lo_release+0x78/0x190 drivers/block/loop.c:1668 1 lock held by blkid/3045: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1405 1 lock held by blkid/3048: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 1 lock held by blkid/3052: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 1 lock held by blkid/3054: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.105+ #29 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: 0 Comm: swapper/0 Not tainted 4.14.105+ #29 task: ffffffffa5c31200 task.stack: ffffffffa5c00000 RIP: 0010:cpumask_next_and+0x12/0xa0 lib/cpumask.c:35 RSP: 0018:ffff8881dba078d0 EFLAGS: 00000246 RAX: ffffed103b740fa2 RBX: ffff8881dba07ad8 RCX: 1ffffffff4c06939 RDX: ffff8881dba1e4b8 RSI: ffff8881da96af28 RDI: 0000000000000000 RBP: 000000000002a200 R08: 0000000000000001 R09: ffff8881dba2a200 R10: ffffed103b740f64 R11: ffff8881dba07b27 R12: ffff8881dba2a200 R13: ffff8881da96af28 R14: ffff8881dba1e4b8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881dba00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000781f04 CR3: 00000001bc626005 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: update_sg_lb_stats kernel/sched/fair.c:9497 [inline] update_sd_lb_stats kernel/sched/fair.c:9746 [inline] find_busiest_group+0x3b8/0x3950 kernel/sched/fair.c:10083 load_balance+0x3f9/0x2a00 kernel/sched/fair.c:10395 rebalance_domains+0x785/0xd50 kernel/sched/fair.c:11091 run_rebalance_domains+0x60f/0x8e0 kernel/sched/fair.c:11355 __do_softirq+0x234/0x9ca kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x114/0x150 kernel/softirq.c:409 reschedule_interrupt+0x84/0x90 arch/x86/entry/entry_64.S:811 RIP: 0010:native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:58 RSP: 0018:ffffffffa5c07d48 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff02 RAX: 0000000000000007 RBX: ffffffffa602a508 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffffa5c31a2c RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffffa5c31200 R15: dffffc0000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x50/0x390 arch/x86/kernel/process.c:564 cpuidle_idle_call kernel/sched/idle.c:159 [inline] do_idle+0x2e6/0x390 kernel/sched/idle.c:268 cpu_startup_entry+0xc6/0xd0 kernel/sched/idle.c:374 start_kernel+0x712/0x74a init/main.c:710 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 Code: 48 63 d2 e8 81 75 37 ff 5b 5d c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 41 57 41 89 ff 41 56 49 89 d6 41 55 49 89 f5 41 54 55 <48> c7 c5 c4 4a 03 a6 49 89 ec 53 83 e5 07 e8 eb 15 b1 fe 49 c1