================================================================== EXT4-fs (sda1): re-mounted. Opts: noblock_validity,,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 ffff8801c5fac750 by task syz-executor5/6212 netlink: 3 bytes leftover after parsing attributes in process `syz-executor1'. CPU: 1 PID: 6212 Comm: syz-executor5 Not tainted 4.20.0-rc1-next-20181109+ #110 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 netlink: 'syz-executor1': attribute type 3 has an invalid length. print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 netlink: 3 bytes leftover after parsing attributes in process `syz-executor1'. kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+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.80+0xc1/0x210 fs/ext4/inode.c:402 netlink: 'syz-executor1': attribute type 3 has an invalid length. ext4_map_blocks+0x1021/0x1b50 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: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 mountpoint_last fs/namei.c:2665 [inline] path_mountpoint+0x6e4/0x2180 fs/namei.c:2695 filename_mountpoint+0x245/0x460 fs/namei.c:2717 user_path_mountpoint_at+0x37/0x40 fs/namei.c:2747 ksys_umount+0x1c5/0x1260 fs/namespace.c:1626 __do_sys_umount fs/namespace.c:1652 [inline] __se_sys_umount fs/namespace.c:1650 [inline] __x64_sys_umount+0x54/0x80 fs/namespace.c:1650 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459fb7 Code: 44 00 00 b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 9d 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 7d 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffd25ff7f68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 000000000005a221 RCX: 0000000000459fb7 RDX: 000000000000000c RSI: 0000000000000002 RDI: 00007ffd25ff90a0 RBP: 00000000000002ad R08: 0000000000000001 R09: 0000000000cc4940 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd25ff90a0 R13: 000000000005a1f4 R14: 0000000000000000 R15: 0000000000000005 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+0x89eb/0xdba0 fs/ext4/super.c:4386 mount_bdev+0x314/0x3e0 fs/super.c:1356 ext4_mount+0x3c/0x50 fs/ext4/super.c:5896 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+0x69b/0x6b4 init/main.c:1159 kernel_init+0x11/0x1ae init/main.c:1060 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Freed by task 11536: 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+0x16fc/0x2980 fs/ext4/super.c:5341 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 ffff8801c5fac738 which belongs to the cache ext4_system_zone of size 40 The buggy address is located 24 bytes inside of 40-byte region [ffff8801c5fac738, ffff8801c5fac760) The buggy address belongs to the page: page:ffffea000717eb00 count:1 mapcount:0 mapping:ffff8801d451ea80 index:0xffff8801c5facfb9 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffff8801d4518538 ffff8801d4518538 ffff8801d451ea80 raw: ffff8801c5facfb9 ffff8801c5fac000 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c5fac600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801c5fac680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801c5fac700: fc fc fc fc fc fc fc fb fb fb fb fb fc fc fb fb ^ ffff8801c5fac780: fb fb fb fc fc fb fb fb fb fb fc fc fb fb fb fb ffff8801c5fac800: fb fc fc fb fb fb fb fb fc fc fb fb fb fb fb fc ==================================================================