================================================================== BUG: KASAN: use-after-free in disk_unblock_events+0x4b/0x50 block/genhd.c:1644 Read of size 8 at addr ffff8881c6bee2e8 by task syz-executor100/4340 CPU: 0 PID: 4340 Comm: syz-executor100 Not tainted 4.14.106+ #30 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 print_address_description+0x60/0x226 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0x88/0x2a5 mm/kasan/report.c:393 Allocated by task 4315: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x126/0x310 mm/slub.c:2750 kmem_cache_alloc_node_trace include/linux/slab.h:378 [inline] kmalloc_node include/linux/slab.h:526 [inline] kzalloc_node include/linux/slab.h:672 [inline] alloc_disk_node+0x5b/0x3d0 block/genhd.c:1387 Freed by task 4340: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xb0/0x190 mm/kasan/kasan.c:524 slab_free_hook mm/slub.c:1389 [inline] slab_free_freelist_hook mm/slub.c:1410 [inline] slab_free mm/slub.c:2966 [inline] kfree+0xf5/0x310 mm/slub.c:3897 device_release+0xf4/0x1a0 drivers/base/core.c:822 The buggy address belongs to the object at ffff8881c6bedd80 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 1384 bytes inside of 2048-byte region [ffff8881c6bedd80, ffff8881c6bee580) The buggy address belongs to the page: page:ffffea00071afa00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000008100(slab|head) raw: 4000000000008100 0000000000000000 0000000000000000 00000001000f000f raw: dead000000000100 dead000000000200 ffff8881da802800 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881c6bee180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881c6bee200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881c6bee280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881c6bee300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881c6bee380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================