[PATCH 4.19 068/105] ext4: ignore e_value_offs for xattrs with value-in-ea-inode

[Greg Kroah-Hartman]

From: Theodore Ts'o <tytso@xxxxxxx>

commit e5d01196c0428a206f307e9ee5f6842964098ff0 upstream.

In other places in fs/ext4/xattr.c, if e_value_inum is non-zero, the
code ignores the value in e_value_offs.  The e_value_offs *should* be
zero, but we shouldn't depend upon it, since it might not be true in a
corrupted/fuzzed file system.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202897
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202877
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Cc: stable@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/ext4/xattr.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1700,7 +1700,7 @@ static int ext4_xattr_set_entry(struct e
 
 	/* No failures allowed past this point. */
 
-	if (!s->not_found && here->e_value_size && here->e_value_offs) {
+	if (!s->not_found && here->e_value_size && !here->e_value_inum) {
 		/* Remove the old value. */
 		void *first_val = s->base + min_offs;
 		size_t offs = le16_to_cpu(here->e_value_offs);