Revert "ucounts: Increase ucounts reference counter before the securi…

…ty hook"

This reverts commit b493af3 which is
commit bbb6d0f upstream.

The "original" commit 905ae01 ("Add a reference to ucounts for each
cred"), should not have been applied to the 5.10.y tree, so revert it,
and the follow-on fixup patches as well.

Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/87v93k4bl6.fsf@disp2133
Cc: Alexey Gladkov <legion@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/cred.c

@@ -286,11 +286,11 @@ struct cred *prepare_creds(void)
 	new->security = NULL;
 #endif
 
-	new->ucounts = get_ucounts(new->ucounts);
-	if (!new->ucounts)
+	if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
 		goto error;
 
-	if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
+	new->ucounts = get_ucounts(new->ucounts);
+	if (!new->ucounts)
 		goto error;
 
 	validate_creds(new);
@@ -753,11 +753,11 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon)
 #ifdef CONFIG_SECURITY
 	new->security = NULL;
 #endif
-	new->ucounts = get_ucounts(new->ucounts);
-	if (!new->ucounts)
+	if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
 		goto error;
 
-	if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
+	new->ucounts = get_ucounts(new->ucounts);
+	if (!new->ucounts)
 		goto error;
 
 	put_cred(old);