random: sshd: uninitialized urandom read (32 bytes read) audit: type=1400 audit(1555445329.679:7): avc: denied { map } for pid=1800 comm="syz-executor908" path="/root/syz-executor908997611" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 ================================================================== BUG: KASAN: use-after-free in get_disk+0xc0/0xd0 block/genhd.c:1433 Read of size 8 at addr ffff8881cf4d1eb0 by task blkid/1806 CPU: 1 PID: 1806 Comm: blkid Not tainted 4.14.111+ #54 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 1801: 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 1803: 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 ffff8881cf4d1980 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 1328 bytes inside of 2048-byte region [ffff8881cf4d1980, ffff8881cf4d2180) The buggy address belongs to the page: page:ffffea00073d3400 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 0000000000000000 0000000000000000 00000001800f000f raw: dead000000000100 dead000000000200 ffff8881da802800 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881cf4d1d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881cf4d1e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881cf4d1e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881cf4d1f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881cf4d1f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================