================================================================== BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 block/genhd.c:1550 Read of size 8 at addr ffff8801c92540e0 by task blkid/7360 CPU: 0 PID: 7360 Comm: blkid Not tainted 4.9.128+ #41 ffff8801c80df6f8 ffffffff81af2469 ffffea0007249400 ffff8801c92540e0 0000000000000000 ffff8801c92540e0 0000000000000000 ffff8801c80df730 ffffffff814e13cb ffff8801c92540e0 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 [] disk_unblock_events+0x51/0x60 block/genhd.c:1550 [] __blkdev_get+0x6b6/0xd60 fs/block_dev.c:1360 [] blkdev_get+0x2da/0x920 fs/block_dev.c:1416 [] blkdev_open+0x1a5/0x250 fs/block_dev.c:1571 [] do_dentry_open+0x3ef/0xc90 fs/open.c:766 [] vfs_open+0x11c/0x210 fs/open.c:879 [] do_last fs/namei.c:3410 [inline] [] path_openat+0x542/0x2790 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+0x19f/0x480 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Allocated by task 7351: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack mm/kasan/kasan.c:505 [inline] set_track mm/kasan/kasan.c:517 [inline] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:609 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:594 kmem_cache_alloc_trace+0x117/0x2e0 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:1791 loop_probe+0x14f/0x180 drivers/block/loop.c:1898 kobj_lookup+0x223/0x410 drivers/base/map.c:124 get_gendisk+0x39/0x2d0 block/genhd.c:716 bd_start_claiming fs/block_dev.c:926 [inline] blkdev_get+0xf6/0x920 fs/block_dev.c:1409 blkdev_open+0x1a5/0x250 fs/block_dev.c:1571 do_dentry_open+0x3ef/0xc90 fs/open.c:766 vfs_open+0x11c/0x210 fs/open.c:879 do_last fs/namei.c:3410 [inline] path_openat+0x542/0x2790 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+0x19f/0x480 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb Freed by task 7360: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack mm/kasan/kasan.c:505 [inline] set_track mm/kasan/kasan.c:517 [inline] kasan_slab_free+0xac/0x190 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 lib/kobject.c:672 [inline] kref_sub include/linux/kref.h:73 [inline] kref_put include/linux/kref.h:98 [inline] kobject_put+0x148/0x250 lib/kobject.c:689 put_disk+0x23/0x30 block/genhd.c:1358 __blkdev_get+0x616/0xd60 fs/block_dev.c:1353 blkdev_get+0x2da/0x920 fs/block_dev.c:1416 blkdev_open+0x1a5/0x250 fs/block_dev.c:1571 do_dentry_open+0x3ef/0xc90 fs/open.c:766 vfs_open+0x11c/0x210 fs/open.c:879 do_last fs/namei.c:3410 [inline] path_openat+0x542/0x2790 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+0x19f/0x480 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb The buggy address belongs to the object at ffff8801c9253b80 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 1376 bytes inside of 2048-byte region [ffff8801c9253b80, ffff8801c9254380) The buggy address belongs to the page: page:ffffea0007249400 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000004080(slab|head) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c9253f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c9254000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801c9254080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801c9254100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c9254180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================