Patch "crypto: drbg - wait for crypto op not signal safe" has been added to the 4.9-stable tree

Patch "crypto: drbg - wait for crypto op not signal safe" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    crypto: drbg - wait for crypto op not signal safe

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     crypto-drbg-wait-for-crypto-op-not-signal-safe.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From a5dfefb1c3f3db81662556393fd9283511e08430 Mon Sep 17 00:00:00 2001
From: Gilad Ben-Yossef <gilad@benyossef.com>
Date: Thu, 18 May 2017 16:29:24 +0300
Subject: crypto: drbg - wait for crypto op not signal safe

From: Gilad Ben-Yossef <gilad@benyossef.com>

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>

---
 crypto/drbg.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1768,9 +1768,8 @@ static int drbg_kcapi_sym_ctr(struct drb
 			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;
 			}


Patches currently in stable-queue which might be from gilad@benyossef.com are

queue-4.9/crypto-drbg-wait-for-crypto-op-not-signal-safe.patch
queue-4.9/crypto-gcm-wait-for-crypto-op-not-signal-safe.patch
queue-4.9/crypto-asymmetric_keys-handle-ebusy-due-to-backlog-correctly.patch