Lowmem check does not skip invalid type in extent_inline_ref then calls btrfs_extent_inline_ref_size(type) which causes crash.
Example: $ ./btrfs-corrupt-block -e -l 20971520 /tmp/data_small corrupting extent record: key 20971520 169 0 $ btrfs check --mode=lowmem /tmp/data_small Checking filesystem on /tmp/data_small UUID: ee205d69-8724-4aa2-a4f5-bc8558a62169 checking extents ERROR: extent[20971520 16384] backref type mismatch, missing bit: 2 ERROR: extent[20971520 16384] backref generation mismatch, wanted: 7, have: 0 ERROR: extent[20971520 16384] is referred by other roots than 3 ctree.h:1754: btrfs_extent_inline_ref_size: BUG_ON `1` triggered, value 1 btrfs(+0x543db)[0x55fabc2ab3db] btrfs(+0x587f7)[0x55fabc2af7f7] btrfs(+0x5fa44)[0x55fabc2b6a44] btrfs(cmd_check+0x194a)[0x55fabc2bd717] btrfs(main+0x88)[0x55fabc2682e0] /usr/lib/libc.so.6(__libc_start_main+0xea)[0x7f021c3824ca] btrfs(_start+0x2a)[0x55fabc267e7a] [1] 5188 abort (core dumped) btrfs check --mode=lowmem /tmp/data_small Fix it by checking type before obtaining inline_ref size. Signed-off-by: Su Yue <suy.f...@cn.fujitsu.com> --- cmds-check.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/cmds-check.c b/cmds-check.c index 4e0b0fe4..74c10c75 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -11565,6 +11565,10 @@ static int check_tree_block_ref(struct btrfs_root *root, offset, level + 1, owner, NULL); } + } else { + error("extent[%llu %u %llu] has unknown ref type: %d", + key.objectid, key.type, key.offset, type); + break; } if (found_ref) @@ -11831,6 +11835,11 @@ static int check_extent_data_item(struct btrfs_root *root, found_dbackref = !check_tree_block_ref(root, NULL, btrfs_extent_inline_ref_offset(leaf, iref), 0, owner, NULL); + } else { + error("extent[%llu %u %llu] has unknown ref type: %d", + disk_bytenr, BTRFS_EXTENT_DATA_KEY, + disk_num_bytes, type); + break; } if (found_dbackref) -- 2.14.1 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html