fs: NULL dereference in posix_acl_to_xattr()

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

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 38bae5a0ea257ebc414aef89727f3a652d904c96..202b84fd33103727428e1211f20751193337a67c 100644 (file)
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -717,7 +717,7 @@ 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);
@@ -725,7 +725,8 @@ 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++) {