================================================================== BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 block/genhd.c:1657 Read of size 8 at addr ffff8801bbb43340 by task blkid/24268 CPU: 0 PID: 24268 Comm: blkid Not tainted 4.15.0-rc8+ #265 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 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 disk_unblock_events+0x51/0x60 block/genhd.c:1657 __blkdev_get+0x869/0x10e0 fs/block_dev.c:1535 blkdev_get+0x3a1/0xad0 fs/block_dev.c:1591 blkdev_open+0x1c9/0x250 fs/block_dev.c:1749 do_dentry_open+0x667/0xd40 fs/open.c:752 vfs_open+0x107/0x220 fs/open.c:866 do_last fs/namei.c:3379 [inline] path_openat+0x1151/0x3530 fs/namei.c:3519 do_filp_open+0x25b/0x3b0 fs/namei.c:3554 do_sys_open+0x502/0x6d0 fs/open.c:1059 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x7fe8196b7120 RSP: 002b:00007fff5aee5a88 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fe819b9887c RCX: 00007fe8196b7120 RDX: 00007fff5aee7f43 RSI: 0000000000000000 RDI: 00007fff5aee7f43 RBP: 00007fff5aee7f3b R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403738 R13: 0000000000000001 R14: 0000000000000000 R15: 00007fe81998da20 Allocated by task 24259: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_node_trace+0x150/0x750 mm/slab.c:3653 kmalloc_node include/linux/slab.h:537 [inline] kzalloc_node include/linux/slab.h:699 [inline] __alloc_disk_node+0xb4/0x4e0 block/genhd.c:1400 loop_add+0x44c/0xa70 drivers/block/loop.c:1814 loop_control_ioctl+0x129/0x490 drivers/block/loop.c:1946 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 Freed by task 24268: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3488 [inline] kfree+0xd6/0x260 mm/slab.c:3803 disk_release+0x327/0x410 block/genhd.c:1249 device_release+0x7c/0x210 drivers/base/core.c:814 kobject_cleanup lib/kobject.c:648 [inline] kobject_release lib/kobject.c:677 [inline] kref_put include/linux/kref.h:70 [inline] kobject_put+0x14c/0x250 lib/kobject.c:694 put_disk+0x23/0x30 block/genhd.c:1465 __blkdev_get+0x7c9/0x10e0 fs/block_dev.c:1528 blkdev_get+0x3a1/0xad0 fs/block_dev.c:1591 blkdev_open+0x1c9/0x250 fs/block_dev.c:1749 do_dentry_open+0x667/0xd40 fs/open.c:752 vfs_open+0x107/0x220 fs/open.c:866 do_last fs/namei.c:3379 [inline] path_openat+0x1151/0x3530 fs/namei.c:3519 do_filp_open+0x25b/0x3b0 fs/namei.c:3554 do_sys_open+0x502/0x6d0 fs/open.c:1059 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 entry_SYSCALL_64_fastpath+0x29/0xa0 The buggy address belongs to the object at ffff8801bbb42dc0 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 1408 bytes inside of 2048-byte region [ffff8801bbb42dc0, ffff8801bbb435c0) The buggy address belongs to the page: page:ffffea0006eed080 count:1 mapcount:0 mapping:ffff8801bbb42540 index:0xffff8801bbb42540 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801bbb42540 ffff8801bbb42540 0000000100000002 raw: ffffea00070544a0 ffffea0007511d20 ffff8801dac00c40 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801bbb43200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801bbb43280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801bbb43300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801bbb43380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801bbb43400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================