================================================================== BUG: KASAN: use-after-free in get_disk+0xc2/0xd0 block/genhd.c:1339 Read of size 8 at addr ffff8801cb6e0528 by task syz-executor5/29841 CPU: 0 PID: 29841 Comm: syz-executor5 Not tainted 4.9.109-g7cecc75 #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801790e7698 ffffffff81eb3e29 ffffea00072db800 ffff8801cb6e0528 0000000000000000 ffff8801cb6e0528 0000000000000000 ffff8801790e76d0 ffffffff81567a89 ffff8801cb6e0528 0000000000000008 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x6c/0x234 mm/kasan/report.c:256 [] kasan_report_error mm/kasan/report.c:355 [inline] [] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 [] get_disk+0xc2/0xd0 block/genhd.c:1339 [] get_gendisk+0x16a/0x2d0 block/genhd.c:724 [] __blkdev_get+0x351/0xd60 fs/block_dev.c:1262 [] blkdev_get+0x2da/0x920 fs/block_dev.c:1416 [] blkdev_open+0x1a5/0x250 fs/block_dev.c:1571 [] do_dentry_open+0x703/0xc80 fs/open.c:766 [] vfs_open+0x11c/0x210 fs/open.c:879 [] do_last fs/namei.c:3410 [inline] [] path_openat+0x758/0x3590 fs/namei.c:3534 [] do_filp_open+0x197/0x270 fs/namei.c:3568 [] do_sys_open+0x30d/0x5c0 fs/open.c:1072 [] SYSC_open fs/open.c:1090 [inline] [] SyS_open+0x2d/0x40 fs/open.c:1085 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Allocated by task 25339: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:609 kmem_cache_alloc_trace+0xfd/0x2b0 mm/slub.c:2742 kmem_cache_alloc_node_trace include/linux/slab.h:381 [inline] kmalloc_node include/linux/slab.h:528 [inline] kzalloc_node include/linux/slab.h:647 [inline] alloc_disk_node+0x54/0x3a0 block/genhd.c:1294 alloc_disk+0x18/0x20 block/genhd.c:1286 loop_add+0x33b/0x770 drivers/block/loop.c:1782 loop_control_ioctl+0x136/0x300 drivers/block/loop.c:1914 vfs_ioctl fs/ioctl.c:43 [inline] file_ioctl fs/ioctl.c:493 [inline] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677 SYSC_ioctl fs/ioctl.c:694 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685 do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb Freed by task 26898: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:582 slab_free_hook mm/slub.c:1355 [inline] slab_free_freelist_hook mm/slub.c:1377 [inline] slab_free mm/slub.c:2958 [inline] kfree+0xfb/0x310 mm/slub.c:3878 disk_release+0x259/0x330 block/genhd.c:1147 device_release+0x7e/0x220 drivers/base/core.c:247 kobject_cleanup lib/kobject.c:643 [inline] kobject_release+0x103/0x1b0 lib/kobject.c:672 kref_sub include/linux/kref.h:73 [inline] kref_put include/linux/kref.h:98 [inline] kobject_put+0x6d/0xd0 lib/kobject.c:689 put_disk+0x23/0x30 block/genhd.c:1358 __blkdev_get+0x57d/0xd60 fs/block_dev.c:1374 blkdev_get+0x2da/0x920 fs/block_dev.c:1416 blkdev_open+0x1a5/0x250 fs/block_dev.c:1571 do_dentry_open+0x703/0xc80 fs/open.c:766 vfs_open+0x11c/0x210 fs/open.c:879 do_last fs/namei.c:3410 [inline] path_openat+0x758/0x3590 fs/namei.c:3534 do_filp_open+0x197/0x270 fs/namei.c:3568 do_sys_open+0x30d/0x5c0 fs/open.c:1072 SYSC_open fs/open.c:1090 [inline] SyS_open+0x2d/0x40 fs/open.c:1085 do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb The buggy address belongs to the object at ffff8801cb6e0000 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 1320 bytes inside of 2048-byte region [ffff8801cb6e0000, ffff8801cb6e0800) The buggy address belongs to the page: page:ffffea00072db800 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x8000000000004080(slab|head) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801cb6e0400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801cb6e0480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801cb6e0500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801cb6e0580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801cb6e0600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================