crypto: asymmetric_keys - handle EBUSY due to backlog correctly

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

diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index d3a989e718f53518bafe93ddb9efea419e5d9b30..3cd6e12cfc467d27ccf2830fffde82e1aaf0f45e 100644 (file)
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -141,7 +141,7 @@ int public_key_verify_signature(const struct public_key *pkey,
         * 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;
        }