Patch "crypto: asymmetric_keys - handle EBUSY due to backlog correctly" has been added to the 4.9-stable tree

Patch "crypto: asymmetric_keys - handle EBUSY due to backlog correctly" 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: asymmetric_keys - handle EBUSY due to backlog correctly

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-asymmetric_keys-handle-ebusy-due-to-backlog-correctly.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 e68368aed56324e2e38d4f6b044bb8cf82077fc2 Mon Sep 17 00:00:00 2001
From: Gilad Ben-Yossef <gilad@benyossef.com>
Date: Thu, 18 May 2017 16:29:23 +0300
Subject: crypto: asymmetric_keys - handle EBUSY due to backlog correctly

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

commit e68368aed56324e2e38d4f6b044bb8cf82077fc2 upstream.

public_key_verify_signature() was passing the CRYPTO_TFM_REQ_MAY_BACKLOG
flag to akcipher_request_set_callback() but was not handling correctly
the case where a -EBUSY error could be returned from the call to
crypto_akcipher_verify() if backlog was used, possibly casuing
data corruption due to use-after-free of buffers.

Resolve this by handling -EBUSY correctly.

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/asymmetric_keys/public_key.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -140,7 +140,7 @@ int public_key_verify_signature(const st
 	 * signature and returns that to us.
 	 */
 	ret = crypto_akcipher_verify(req);
-	if (ret == -EINPROGRESS) {
+	if ((ret == -EINPROGRESS) || (ret == -EBUSY)) {
 		wait_for_completion(&compl.completion);
 		ret = compl.err;
 	}


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