[PATCH 5.0 084/123] ext4: ignore e_value_offs for xattrs with value-in-ea-inode

From: Greg Kroah-Hartman
Date: Mon May 20 2019 - 08:31:31 EST


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
@@ -1696,7 +1696,7 @@ 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);