From: Gilad Ben-Yossef <gilad@benyossef.com>
Date: Thu, 18 May 2017 13:29:24 +0000 (+0300)
Subject: crypto: drbg - wait for crypto op not signal safe
X-Git-Tag: v4.11.5~110
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1286652e80cc3c847ca23aac4a91ecd232095ff9;p=thirdparty%2Fkernel%2Fstable.git

crypto: drbg - wait for crypto op not signal safe

commit a5dfefb1c3f3db81662556393fd9283511e08430 upstream.

drbg_kcapi_sym_ctr() was using wait_for_completion_interruptible() to
wait for completion of async crypto op but if a signal occurs it
may return before DMA ops of HW crypto provider finish, thus
corrupting the output buffer.

Resolve this by using wait_for_completion() instead.

Reported-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/crypto/drbg.c b/crypto/drbg.c
index 8a4d98b4adba4..5efc2b22a8311 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1768,9 +1768,8 @@ static int drbg_kcapi_sym_ctr(struct drbg_state *drbg,
 			break;
 		case -EINPROGRESS:
 		case -EBUSY:
-			ret = wait_for_completion_interruptible(
-				&drbg->ctr_completion);
-			if (!ret && !drbg->ctr_async_err) {
+			wait_for_completion(&drbg->ctr_completion);
+			if (!drbg->ctr_async_err) {
 				reinit_completion(&drbg->ctr_completion);
 				break;
 			}