audit: type=1400 audit(1595328646.933:8): avc: denied { execmem } for pid=6341 comm="syz-executor043" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 INFO: task syz-executor043:6342 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor043 D28672 6342 6335 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x1fc/0x380 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:66 [inline] down_read+0x45/0xa0 kernel/locking/rwsem.c:26 __get_super.part.0+0x1c6/0x280 fs/super.c:678 __get_super include/linux/spinlock.h:317 [inline] get_super+0x2b/0x50 fs/super.c:707 fsync_bdev+0x14/0xd0 fs/block_dev.c:495 invalidate_partition+0x31/0x60 block/genhd.c:1506 drop_partitions block/partition-generic.c:442 [inline] rescan_partitions+0xe1/0x860 block/partition-generic.c:515 __blkdev_reread_part+0x140/0x1d0 block/ioctl.c:173 blkdev_reread_part+0x23/0x40 block/ioctl.c:193 loop_reread_partitions+0x72/0x80 drivers/block/loop.c:624 loop_set_status+0xbfd/0x11f0 drivers/block/loop.c:1193 loop_set_status64+0x92/0xe0 drivers/block/loop.c:1311 lo_ioctl+0x587/0x1c00 drivers/block/loop.c:1441 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x91d/0x17c0 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+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x445b27 RSP: 002b:00007fd982950b68 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000445b27 RDX: 00007fd982950c00 RSI: 0000000000004c04 RDI: 0000000000000004 RBP: 00007fd9829516d0 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000202 R12: 00000000006dac2c R13: 00007ffe324e52cf R14: 0000000000000004 R15: 20c49ba5e353f7cf INFO: task syz-executor043:6346 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor043 D29312 6346 6335 0x80000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 lo_ioctl+0x87/0x1c00 drivers/block/loop.c:1414 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x91d/0x17c0 block/ioctl.c:594 ioctl_by_bdev+0xa0/0x110 fs/block_dev.c:2066 isofs_get_last_session fs/isofs/inode.c:571 [inline] isofs_fill_super+0x1cb5/0x25b0 fs/isofs/inode.c:670 mount_bdev+0x2b3/0x360 fs/super.c:1134 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x3c9/0x25e0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x445c19 RSP: 002b:00007fd98292fdb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00000000006dac38 RCX: 0000000000445c19 RDX: 0000000020000080 RSI: 0000000020000200 RDI: 0000000020000340 RBP: 00000000006dac30 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac3c R13: 00007ffe324e52cf R14: 00007fd9829309c0 R15: 20c49ba5e353f7cf Showing all locks held in the system: 1 lock held by khungtaskd/1057: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 3 locks held by syz-executor043/6342: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1c00 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 #2: (&type->s_umount_key#57){.+.+}, at: [] __get_super.part.0+0x1c6/0x280 fs/super.c:678 2 locks held by syz-executor043/6346: #0: (&type->s_umount_key#56/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] #0: (&type->s_umount_key#56/1){+.+.}, at: [] sget_userns+0x556/0xc30 fs/super.c:516 #1: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1c00 drivers/block/loop.c:1414 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1057 Comm: khungtaskd Not tainted 4.14.184-syzkaller #0 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+0x1b2/0x283 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x17f lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e2/0xb80 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8 Comm: rcu_preempt Not tainted 4.14.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a9cde200 task.stack: ffff8880a9ce8000 RIP: 0010:__lock_acquire+0x24c/0x42a0 kernel/locking/lockdep.c:3396 RSP: 0018:ffff8880a9cef8f0 EFLAGS: 00000002 RAX: ffffffff89ea1230 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 1ffff11015da56b4 RSI: 0000000000000000 RDI: ffff8880aed2b5a0 RBP: ffff8880a9cefaa0 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: ffff8880a9cde200 R12: ffff8880aed2b598 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc245dcf000 CR3: 0000000094592000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 finish_lock_switch kernel/sched/sched.h:1350 [inline] finish_task_switch+0x170/0x610 kernel/sched/core.c:2675 context_switch kernel/sched/core.c:2811 [inline] __schedule+0x8ae/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x4df/0xe50 kernel/time/timer.c:1746 rcu_gp_kthread+0xb3d/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 4b 8d 7c ec 08 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 ba 2b 00 00 4b 8b 44 ec 08 48 85 c0 0f 84 15 ff ff ff f0 ff 80 38 01 00 00 <49> 8d b3 80 08 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 b4 24