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authorTheodore Ts'o <tytso@mit.edu>2018-06-16 15:40:48 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-10-10 08:52:08 +0200
commitcd3d6463759d21f4093d3434effacc358dd0caf8 (patch)
treec214df54321a3d408318f81bb1d14eb22114a972 /fs
parent14a65511bc7c1eec560764fe53018b0765fb8d2d (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> Cc: stable@kernel.org Signed-off-by: Zubin Mithra <zsm@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-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 9fb2a751fce4..b51bb73b06a6 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1386,6 +1386,11 @@ 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);