If there an inode points to a block which is also some other type of metadata block (such as a block allocation bitmap), the buffer_verified flag can be set when it was validated as that other metadata block type; however, it would make a really terrible external attribute block. The reason why we use the verified flag is to avoid constantly reverifying the block. However, it doesn't take much overhead to make sure the magic number of the xattr block is correct, and this will avoid potential crashes. https://bugzilla.kernel.org/show_bug.cgi?id=200001 https://bugzilla.kernel.org/show_bug.cgi?id=199997 Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> --- fs/ext4/xattr.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 230ba79715f6..0263692979ec 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -230,12 +230,12 @@ __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh, { int error = -EFSCORRUPTED; - if (buffer_verified(bh)) - return 0; - if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || BHDR(bh)->h_blocks != cpu_to_le32(1)) goto errout; + if (buffer_verified(bh)) + return 0; + error = -EFSBADCRC; if (!ext4_xattr_block_csum_verify(inode, bh)) goto errout; -- 2.18.0.rc0
