From e386b9287718c94905465e5e7ed90f0e3c570bf8 Mon Sep 17 00:00:00 2001
From: Sascha Hauer <s.hauer@pengutronix.de>
Date: Tue, 2 Jul 2019 10:00:41 +0200
Subject: [PATCH] ima: fix freeing ongoing ahash_request

commit 4ece3125f21b1d42b84896c5646dbf0e878464e1 upstream.

integrity_kernel_read() can fail in which case we forward to call
ahash_request_free() on a currently running request. We have to wait
for its completion before we can free the request.

This was observed by interrupting a "find / -type f -xdev -print0 | xargs -0
cat 1>/dev/null" with ctrl-c on an IMA enabled filesystem.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 7532b062be59..73044fc6a952 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -271,6 +271,11 @@ static int ima_calc_file_hash_atfm(struct file *file,
 		if (rc != rbuf_len) {
 			if (rc >= 0)
 				rc = -EINVAL;
+			/*
+			 * Forward current rc, do not overwrite with return value
+			 * from ahash_wait()
+			 */
+			ahash_wait(ahash_rc, &wait);
 			goto out3;
 		}
 
-- 
2.7.4