ext4: fix ext4_xattr_cmp()

When a xattr entry refers to an external inode, the value data is not
available in the inline area so we should not attempt to read it using
value offset.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index bd1e61a0c228..ed27b5241e69 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2167,7 +2167,8 @@ ext4_xattr_cmp(struct ext4_xattr_header *header1,
                     entry1->e_value_inum != entry2->e_value_inum ||
                     memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
                         return 1;
-                if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
+                if (!entry1->e_value_inum &&
+                    memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
                            (char *)header2 + le16_to_cpu(entry2->e_value_offs),
                            le32_to_cpu(entry1->e_value_size)))
                         return 1;