[PATCH] hfsplus: add missing osx prefix to FinderInfo attribute check

[Thomas Hebb <tommyhebb@gmail.com>]

By the time we reach strcmp_xattr_finder_info(), hfsplus_osx_getxattr()
has already prefixed the user-provided xattr name with "osx.", so the
existing check for the special FinderInfo attribute will always fail,
and ENODATA will be returned to userspace.

Since hfsplus_listxattr() reports the FinderInfo attribute, this
behavior causes certain userspace utilities (e.g. patch) to fail, since
the kernel lists an attribute that doesn't exist.

Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Sergei Antonov <saproj@gmail.com>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
---
 fs/hfsplus/xattr.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
index d98094a..da0664e 100644
--- a/fs/hfsplus/xattr.c
+++ b/fs/hfsplus/xattr.c
@@ -28,8 +28,16 @@ const struct xattr_handler *hfsplus_xattr_handlers[] = {
  static int strcmp_xattr_finder_info(const char *name)
 {
+	int err = 0;
+
 	if (name) {
-		return strncmp(name, HFSPLUS_XATTR_FINDER_INFO_NAME,
+		err = strncmp(name, XATTR_MAC_OSX_PREFIX,
+				XATTR_MAC_OSX_PREFIX_LEN);
+		if (err)
+			return err;
+
+		return strncmp(name + XATTR_MAC_OSX_PREFIX_LEN,
+				HFSPLUS_XATTR_FINDER_INFO_NAME,
 				sizeof(HFSPLUS_XATTR_FINDER_INFO_NAME));
 	}
 	return -1;
-- 
2.3.4