From cfcd2271a9076a9891014bc8e18d4fd48acccffe Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Fri, 18 Sep 2015 17:25:36 +0200 Subject: 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 Fixes: db509a45339fd ("crypto: marvell/cesa - add TDMA support") Cc: # v4.2+ Signed-off-by: Thomas Petazzoni Acked-by: Boris Brezillon Tested-by: Vincent Donnefort Signed-off-by: Herbert Xu --- drivers/crypto/marvell/cesa.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'drivers/crypto/marvell/cesa.h') diff --git a/drivers/crypto/marvell/cesa.h b/drivers/crypto/marvell/cesa.h index b60698b30d30..bc2a55bc35e4 100644 --- a/drivers/crypto/marvell/cesa.h +++ b/drivers/crypto/marvell/cesa.h @@ -687,6 +687,33 @@ static inline u32 mv_cesa_get_int_mask(struct mv_cesa_engine *engine) int mv_cesa_queue_req(struct crypto_async_request *req); +/* + * Helper function that indicates whether a crypto request needs to be + * cleaned up or not after being enqueued using mv_cesa_queue_req(). + */ +static inline int mv_cesa_req_needs_cleanup(struct crypto_async_request *req, + int ret) +{ + /* + * The queue still had some space, the request was queued + * normally, so there's no need to clean it up. + */ + if (ret == -EINPROGRESS) + return false; + + /* + * The queue had not space left, but since the request is + * flagged with CRYPTO_TFM_REQ_MAY_BACKLOG, it was added to + * the backlog and will be processed later. There's no need to + * clean it up. + */ + if (ret == -EBUSY && req->flags & CRYPTO_TFM_REQ_MAY_BACKLOG) + return false; + + /* Request wasn't queued, we need to clean it up */ + return true; +} + /* TDMA functions */ static inline void mv_cesa_req_dma_iter_init(struct mv_cesa_dma_iter *iter, -- cgit v1.2.3