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: v4.12-rc5~32^2~1
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=a5dfefb1c3f3db81662556393fd9283511e08430;p=linux.git

crypto: drbg - wait for crypto op not signal safe

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>
CC: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

diff --git a/crypto/drbg.c b/crypto/drbg.c
index fa749f470135..cdb27ac4b226 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1767,9 +1767,8 @@ 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;
 			}