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authorTheodore Ts'o <tytso@mit.edu>2018-06-16 15:40:48 -0400
committerMoyster <oysterized@gmail.com>2018-12-02 01:21:45 +0100
commitdc5179810f810b1df70055fa6da1b14594a9d55b (patch)
tree7a9581049e2602ebd456957fda1f7acd812de0d0 /fs/ext4
parent6739665cbb5188de19fafe00eb103611c07e1bef (diff)
ext4: never move the system.data xattr out of the inode body
commit 8cdb5240ec5928b20490a2bb34cb87e9a5f40226 upstream. When expanding the extra isize space, we must never move the system.data xattr out of the inode body. For performance reasons, it doesn't make any sense, and the inline data implementation assumes that system.data xattr is never in the external xattr block. This addresses CVE-2018-10880 https://bugzilla.kernel.org/show_bug.cgi?id=200005 Signed-off-by: Theodore Ts'o <tytso@mit.edu> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Hackmann <ghackmann@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/xattr.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index c650e0245..bf22326c5 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1418,6 +1418,11 @@ retry:
/* Find the entry best suited to be pushed into EA block */
entry = NULL;
for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+ /* never move system.data out of the inode */
+ if ((last->e_name_len == 4) &&
+ (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
+ !memcmp(last->e_name, "data", 4))
+ continue;
total_size =
EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
EXT4_XATTR_LEN(last->e_name_len);