ext4: fix xattr shifting when expanding inodes part 2

commit 418c12d08dc64a45107c467ec1ba29b5e69b0715 upstream.

When multiple xattrs need to be moved out of inode, we did not properly
recompute total size of xattr headers in the inode and the new header
position. Thus when moving the second and further xattr we asked
ext4_xattr_shift_entries() to move too much and from the wrong place,
resulting in possible xattr value corruption or general memory
corruption.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index bf3130e275ee741361cd102de1ad25246fa39c0e..5b7c078d670915278671cfa940737651a9354cde 100644 (file)
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1423,6 +1423,7 @@ retry:
                error = ext4_xattr_ibody_set(handle, inode, &i, is);
                if (error)
                        goto cleanup;
+               total_ino -= entry_size;
 
                entry = IFIRST(header);
                if (entry_size + EXT4_XATTR_SIZE(size) >= isize_diff)
@@ -1433,11 +1434,11 @@ retry:
                ext4_xattr_shift_entries(entry, -shift_bytes,
                        (void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +
                        EXT4_I(inode)->i_extra_isize + shift_bytes,
-                       (void *)header, total_ino - entry_size,
-                       inode->i_sb->s_blocksize);
+                       (void *)header, total_ino, inode->i_sb->s_blocksize);
 
                isize_diff -= shift_bytes;
                EXT4_I(inode)->i_extra_isize += shift_bytes;
+               header = IHDR(inode, raw_inode);
 
                i.name = b_entry_name;
                i.value = buffer;