R13: 00000000004c1703 R14: 00000000004d32d0 R15: 00000000ffffffff ================================================================== BUG: KASAN: use-after-free in ext4_data_block_valid+0x2d5/0x330 fs/ext4/block_validity.c:211 Read of size 8 at addr ffff8881c531a280 by task blkid/7896 CPU: 0 PID: 7896 Comm: blkid Not tainted 4.20.0-rc6-next-20181217+ #172 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.4+0x9/0x1ff mm/kasan/report.c:187 kasan_report.cold.5+0x1b/0x39 mm/kasan/report.c:317 L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details. __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 ext4_data_block_valid+0x2d5/0x330 fs/ext4/block_validity.c:211 __check_block_validity.constprop.81+0xc1/0x210 fs/ext4/inode.c:402 ext4_map_blocks+0x1012/0x1b30 fs/ext4/inode.c:592 ext4_getblk+0x4f2/0x630 fs/ext4/inode.c:966 ext4_bread_batch+0x7f/0x440 fs/ext4/inode.c:1036 ext4_find_entry+0xd49/0x1b70 fs/ext4/namei.c:1426 ext4_lookup+0x16c/0x750 fs/ext4/namei.c:1558 __lookup_slow+0x2b5/0x540 fs/namei.c:1671 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x92b/0x2590 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.43+0x212/0xc00 fs/namei.c:2318 filename_lookup+0x26a/0x520 fs/namei.c:2348 user_path_at_empty+0x40/0x50 fs/namei.c:2608 user_path_at include/linux/namei.h:57 [inline] do_faccessat+0x254/0x800 fs/open.c:378 __do_sys_access fs/open.c:430 [inline] __se_sys_access fs/open.c:428 [inline] __x64_sys_access+0x59/0x80 fs/open.c:428 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f52eaea6267 Code: 73 01 c3 48 8d 0d 3d af 20 00 31 d2 48 29 c2 89 11 48 83 c8 ff eb eb 90 90 90 90 90 90 90 90 90 90 90 90 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8d 0d 0d af 20 00 31 d2 48 29 c2 89 RSP: 002b:00007ffc0914a208 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 0000000000400f31 RCX: 00007f52eaea6267 RDX: 00000000000033ef RSI: 0000000000000000 RDI: 00007f52eaeaa2e6 RBP: 00007f52eb0a9000 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 00007f52eb0b11c8 R13: 00007f52eb0a9718 R14: 00000000000033ef R15: 00007f52eb0b1570 Allocated by task 1: save_stack+0x43/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] kasan_kmalloc+0xcb/0xd0 mm/kasan/common.c:482 kasan_slab_alloc+0x12/0x20 mm/kasan/common.c:397 kmem_cache_alloc+0x130/0x730 mm/slab.c:3541 add_system_zone+0x2e5/0x5f0 fs/ext4/block_validity.c:85 ext4_setup_system_zone+0x360/0x520 fs/ext4/block_validity.c:160 ext4_fill_super+0x815f/0xda70 fs/ext4/super.c:4491 mount_bdev+0x314/0x3e0 fs/super.c:1356 ext4_mount+0x3c/0x50 fs/ext4/super.c:5999 legacy_get_tree+0x12f/0x260 fs/fs_context.c:714 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1795 do_new_mount fs/namespace.c:2716 [inline] do_mount+0x82a/0x1ff0 fs/namespace.c:3042 ksys_mount+0x12d/0x140 fs/namespace.c:3258 do_mount_root+0x35/0x1d3 init/do_mounts.c:388 mount_block_root+0x39c/0x6ed init/do_mounts.c:417 mount_root+0x358/0x39f init/do_mounts.c:562 prepare_namespace+0x26c/0x2ab init/do_mounts.c:621 kernel_init_freeable+0x6a1/0x6ba init/main.c:1154 kernel_init+0x11/0x1ae init/main.c:1055 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Freed by task 7893: save_stack+0x43/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:444 kasan_slab_free+0xe/0x10 mm/kasan/common.c:452 __cache_free mm/slab.c:3485 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3747 ext4_release_system_zone+0x92/0x110 fs/ext4/block_validity.c:187 ext4_setup_system_zone+0x3ef/0x520 fs/ext4/block_validity.c:151 ext4_remount+0x16fc/0x2980 fs/ext4/super.c:5444 legacy_reconfigure+0x14c/0x1c0 fs/fs_context.c:738 reconfigure_super+0x4c0/0xbb0 fs/super.c:982 do_remount fs/namespace.c:2434 [inline] do_mount+0x1ab4/0x1ff0 fs/namespace.c:3033 ksys_mount+0x12d/0x140 fs/namespace.c:3258 __do_sys_mount fs/namespace.c:3272 [inline] __se_sys_mount fs/namespace.c:3269 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3269 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881c531a268 which belongs to the cache ext4_system_zone of size 40 The buggy address is located 24 bytes inside of 40-byte region [ffff8881c531a268, ffff8881c531a290) The buggy address belongs to the page: page:ffffea000714c680 count:1 mapcount:0 mapping:ffff8881d4657600 index:0xffff8881c531afb9 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffff8881d4651138 ffff8881d4651138 ffff8881d4657600 raw: ffff8881c531afb9 ffff8881c531a000 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881c531a180: fc fb fb fb fb fb fc fc fb fb fb fb fb fc fc fb ffff8881c531a200: fb fb fb fb fc fc fb fb fb fb fb fc fc fb fb fb >ffff8881c531a280: fb fb fc fc fb fb fb fb fb fc fc fb fb fb fb fb ^ ffff8881c531a300: fc fc fb fb fb fb fb fc fc fb fb fb fb fb fc fc ffff8881c531a380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== EXT4-fs (sda1): re-mounted. Opts: barrier,stripe=0x0000000000000401,noblock_validity,max_batch_time=0