crypto: marvell - properly handle CRYPTO_TFM_REQ_MAY_BACKLOG-flagged requests

The mv_cesa_queue_req() function calls crypto_enqueue_request() to
enqueue a request. In the normal case (i.e the queue isn't full), this
function returns -EINPROGRESS. The current Marvell CESA crypto driver
takes this into account and cleans up the request only if an error
occured, i.e if the return value is not -EINPROGRESS.

Unfortunately this causes problems with
CRYPTO_TFM_REQ_MAY_BACKLOG-flagged requests. When such a request is
passed to crypto_enqueue_request() and the queue is full,
crypto_enqueue_request() will return -EBUSY, but will keep the request
enqueued nonetheless. This situation was not properly handled by the
Marvell CESA driver, which was anyway cleaning up the request in such
a situation. When later on the request was taken out of the backlog
and actually processed, a kernel crash occured due to the internal
driver data structures for this structure having been cleaned up.

To avoid this situation, this commit adds a
mv_cesa_req_needs_cleanup() helper function which indicates if the
request needs to be cleaned up or not after a call to
crypto_enqueue_request(). This helper allows to do the cleanup only in
the appropriate cases, and all call sites of mv_cesa_queue_req() are
fixed to use this new helper function.

Reported-by: Vincent Donnefort <vdonnefort@gmail.com>
Fixes: db509a45339fd ("crypto: marvell/cesa - add TDMA support")
Cc: <stable@vger.kernel.org> # v4.2+
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Vincent Donnefort <vdonnefort@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/crypto/marvell/cipher.c b/drivers/crypto/marvell/cipher.c
index 0745cf3b9c0e..3df2f4e7adb2 100644
--- a/drivers/crypto/marvell/cipher.c
+++ b/drivers/crypto/marvell/cipher.c
@@ -189,7 +189,6 @@ static inline void mv_cesa_ablkcipher_prepare(struct crypto_async_request *req,
 {
         struct ablkcipher_request *ablkreq = ablkcipher_request_cast(req);
         struct mv_cesa_ablkcipher_req *creq = ablkcipher_request_ctx(ablkreq);
-
         creq->req.base.engine = engine;
 
         if (creq->req.base.type == CESA_DMA_REQ)
@@ -431,7 +430,7 @@ static int mv_cesa_des_op(struct ablkcipher_request *req,
                 return ret;
 
         ret = mv_cesa_queue_req(&req->base);
-        if (ret && ret != -EINPROGRESS)
+        if (mv_cesa_req_needs_cleanup(&req->base, ret))
                 mv_cesa_ablkcipher_cleanup(req);
 
         return ret;
@@ -551,7 +550,7 @@ static int mv_cesa_des3_op(struct ablkcipher_request *req,
                 return ret;
 
         ret = mv_cesa_queue_req(&req->base);
-        if (ret && ret != -EINPROGRESS)
+        if (mv_cesa_req_needs_cleanup(&req->base, ret))
                 mv_cesa_ablkcipher_cleanup(req);
 
         return ret;
@@ -693,7 +692,7 @@ static int mv_cesa_aes_op(struct ablkcipher_request *req,
                 return ret;
 
         ret = mv_cesa_queue_req(&req->base);
-        if (ret && ret != -EINPROGRESS)
+        if (mv_cesa_req_needs_cleanup(&req->base, ret))
                 mv_cesa_ablkcipher_cleanup(req);
 
         return ret;