==================================================================
EXT4-fs (sda1): re-mounted. Opts: noblock_validity,grpid,usrquota,errors=continue,jqfmt=vfsv0,,errors=continue
BUG: KASAN: use-after-free in ext4_data_block_valid+0x2d5/0x330 fs/ext4/block_validity.c:211
Read of size 8 at addr ffff8801c9ff6750 by task blkid/9321

CPU: 0 PID: 9321 Comm: blkid Not tainted 4.19.0-rc6-next-20181005+ #88
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+0x1d3/0x2c4 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 ext4_data_block_valid+0x2d5/0x330 fs/ext4/block_validity.c:211
 __check_block_validity.constprop.79+0xc1/0x210 fs/ext4/inode.c:402
 ext4_map_blocks+0x1029/0x1b60 fs/ext4/inode.c:592
 ext4_getblk+0x4f2/0x630 fs/ext4/inode.c:966
netlink: 'syz-executor2': attribute type 1 has an invalid length.
netlink: 'syz-executor2': attribute type 1 has an invalid length.
 ext4_bread_batch+0x7f/0x440 fs/ext4/inode.c:1036
 ext4_find_entry+0xd49/0x1b70 fs/ext4/namei.c:1425
 ext4_lookup+0x15b/0x700 fs/ext4/namei.c:1557
 __lookup_slow+0x2b5/0x540 fs/namei.c:1671
 lookup_slow+0x57/0x80 fs/namei.c:1688
 walk_component+0x92b/0x25b0 fs/namei.c:1810
 link_path_walk.part.40+0xa61/0x1530 fs/namei.c:2141
 link_path_walk fs/namei.c:2269 [inline]
 path_lookupat.isra.43+0xf7/0xc00 fs/namei.c:2317
 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: 0033:0x7f3e7cc08267
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:00007ffc8d6a2cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3e7cc08267
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f3e7cc0c2e6
RBP: 00007ffc8d6a2d60 R08: 0000000000000054 R09: 0000000000000000
R10: 00007ffc8d701120 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000004 R14: 00007f3e7ce13758 R15: 00007f3e7cc0c931

Allocated by task 1:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554
 add_system_zone+0x2e5/0x5f0 fs/ext4/block_validity.c:85
 ext4_setup_system_zone+0x208/0x520 fs/ext4/block_validity.c:169
 ext4_fill_super+0x8181/0xdab0 fs/ext4/super.c:4368
 mount_bdev+0x314/0x3e0 fs/super.c:1356
 ext4_mount+0x3c/0x50 fs/ext4/super.c:5872
 legacy_get_tree+0x131/0x460 fs/fs_context.c:718
 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1795
 do_new_mount fs/namespace.c:2648 [inline]
 do_mount+0x70c/0x1d90 fs/namespace.c:2974
 ksys_mount+0x12d/0x140 fs/namespace.c:3190
 do_mount_root+0x35/0x1d3 init/do_mounts.c:388
 mount_block_root+0x39c/0x6ed init/do_mounts.c:417
 mount_root+0x2d3/0x31a init/do_mounts.c:562
 prepare_namespace+0x26c/0x2ab init/do_mounts.c:621
 kernel_init_freeable+0x590/0x5ae init/main.c:1162
 kernel_init+0x11/0x1b2 init/main.c:1063
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Freed by task 9299:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x83/0x290 mm/slab.c:3760
 ext4_release_system_zone+0x7c/0x110 fs/ext4/block_validity.c:187
 ext4_setup_system_zone+0x3ef/0x520 fs/ext4/block_validity.c:151
 ext4_remount+0x1451/0x2640 fs/ext4/super.c:5320
 legacy_reconfigure+0x14c/0x1c0 fs/fs_context.c:754
 reconfigure_super+0x4c0/0xbb0 fs/super.c:982
 do_remount fs/namespace.c:2419 [inline]
 do_mount+0x18b9/0x1d90 fs/namespace.c:2965
 ksys_mount+0x12d/0x140 fs/namespace.c:3190
 __do_sys_mount fs/namespace.c:3204 [inline]
 __se_sys_mount fs/namespace.c:3201 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3201
 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 ffff8801c9ff6738
 which belongs to the cache ext4_system_zone of size 40
The buggy address is located 24 bytes inside of
 40-byte region [ffff8801c9ff6738, ffff8801c9ff6760)
The buggy address belongs to the page:
page:ffffea000727fd80 count:1 mapcount:0 mapping:ffff8801d4e93300 index:0xffff8801c9ff6fb9
flags: 0x2fffc0000000200(slab)
raw: 02fffc0000000200 ffff8801d4e94738 ffff8801d4e94738 ffff8801d4e93300
raw: ffff8801c9ff6fb9 ffff8801c9ff6000 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c9ff6600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801c9ff6680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801c9ff6700: fc fc fc fc fc fc fc fb fb fb fb fb fc fc fb fb
                                                 ^
 ffff8801c9ff6780: fb fb fb fc fc fb fb fb fb fb fc fc fb fb fb fb
 ffff8801c9ff6800: fb fc fc fb fb fb fb fb fc fc fb fb fb fb fb fc
==================================================================