fs: NULL dereference in posix_acl_to_xattr()

commit 47ba9734403770a4c5e685b01f0a72b835dd4fff upstream.

This patch moves the dereference of "buffer" after the check for NULL.
The only place which passes a NULL parameter is gfs2_set_acl().

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 11c54fd..9e363e4 100644 (file)
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -723,7 +723,7 @@ posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl,
                   void *buffer, size_t size)
 {
        posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer;
-       posix_acl_xattr_entry *ext_entry = ext_acl->a_entries;
+       posix_acl_xattr_entry *ext_entry;
        int real_size, n;
 
        real_size = posix_acl_xattr_size(acl->a_count);
@@ -731,7 +731,8 @@ posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl,
                return real_size;
        if (real_size > size)
                return -ERANGE;
-       
+
+       ext_entry = ext_acl->a_entries;
        ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
 
        for (n=0; n < acl->a_count; n++, ext_entry++) {