From: Gilad Ben-Yossef <gilad@benyossef.com>
Date: Thu, 18 May 2017 13:29:25 +0000 (+0300)
Subject: crypto: gcm - wait for crypto op not signal safe
X-Git-Tag: v3.2.93~66
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ed64640fc387a764b18e2961dc9abd5dba22e313;p=thirdparty%2Fkernel%2Fstable.git

crypto: gcm - wait for crypto op not signal safe

commit f3ad587070d6bd961ab942b3fd7a85d00dfc934b upstream.

crypto_gcm_setkey() 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 data buffer that is kfree'ed in this case.

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: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/crypto/gcm.c b/crypto/gcm.c
index dd3bf30f260bc..9f740857f9f98 100644
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -140,10 +140,8 @@ static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
 
 	err = crypto_ablkcipher_encrypt(&data->req);
 	if (err == -EINPROGRESS || err == -EBUSY) {
-		err = wait_for_completion_interruptible(
-			&data->result.completion);
-		if (!err)
-			err = data->result.err;
+		wait_for_completion(&data->result.completion);
+		err = data->result.err;
 	}
 
 	if (err)