[PATCH 1/4] crypto: handle EBUSY due to backlog correctly

From: Gilad Ben-Yossef
Date: Thu May 11 2017 - 07:54:09 EST


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@xxxxxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx
---
crypto/asymmetric_keys/public_key.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index d3a989e..3cd6e12 100644
--- 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;
}
--
2.1.4