Merge tag 'v4.4.21' into android-4.4.y

This is the 4.4.21 stable release

Change-Id: I03e47d6fdca8084641c4b4f9658ea0b0edb8f297

1 files changed, 11 insertions, 8 deletions

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 4f729ffff75d..220b04f04523 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -219,7 +219,7 @@ static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
 }
 
 
-static bool ovl_is_private_xattr(const char *name)
+bool ovl_is_private_xattr(const char *name)
 {
 	return strncmp(name, OVL_XATTR_PRE_NAME, OVL_XATTR_PRE_LEN) == 0;
 }
@@ -277,7 +277,8 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
 	struct path realpath;
 	enum ovl_path_type type = ovl_path_real(dentry, &realpath);
 	ssize_t res;
-	int off;
+	size_t len;
+	char *s;
 
 	res = vfs_listxattr(realpath.dentry, list, size);
 	if (res <= 0 || size == 0)
@@ -287,17 +288,19 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
 		return res;
 
 	/* filter out private xattrs */
-	for (off = 0; off < res;) {
-		char *s = list + off;
-		size_t slen = strlen(s) + 1;
+	for (s = list, len = res; len;) {
+		size_t slen = strnlen(s, len) + 1;
 
-		BUG_ON(off + slen > res);
+		/* underlying fs providing us with an broken xattr list? */
+		if (WARN_ON(slen > len))
+			return -EIO;
 
+		len -= slen;
 		if (ovl_is_private_xattr(s)) {
 			res -= slen;
-			memmove(s, s + slen, res - off);
+			memmove(s, s + slen, len);
 		} else {
-			off += slen;
+			s += slen;
 		}
 	}