crypto: hisilicon - Fix reference after free of memories on error path

coccicheck currently warns of the following issues in the driver:
drivers/crypto/hisilicon/sec/sec_algs.c:864:51-66: ERROR: reference preceded by free on line 812
drivers/crypto/hisilicon/sec/sec_algs.c:864:40-49: ERROR: reference preceded by free on line 813
drivers/crypto/hisilicon/sec/sec_algs.c:861:8-24: ERROR: reference preceded by free on line 814
drivers/crypto/hisilicon/sec/sec_algs.c:860:41-51: ERROR: reference preceded by free on line 815
drivers/crypto/hisilicon/sec/sec_algs.c:867:7-18: ERROR: reference preceded by free on line 816

It would appear than on certain error paths that we may attempt reference-
after-free some memories.

This patch fixes those issues. The solution doesn't look perfect, but
having same memories free'd possibly from separate functions makes it
tricky.

Fixes: 915e4e8413da ("crypto: hisilicon - SEC security accelerator driver")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/hisilicon/sec/sec_algs.c b/drivers/crypto/hisilicon/sec/sec_algs.c
index 32c6c02..cdc4f9a 100644 (file)
--- a/drivers/crypto/hisilicon/sec/sec_algs.c
+++ b/drivers/crypto/hisilicon/sec/sec_algs.c
@@ -808,13 +808,6 @@ static int sec_alg_skcipher_crypto(struct skcipher_request *skreq,
         * more refined but this is unlikely to happen so no need.
         */
 
-       /* Cleanup - all elements in pointer arrays have been coppied */
-       kfree(splits_in_nents);
-       kfree(splits_in);
-       kfree(splits_out_nents);
-       kfree(splits_out);
-       kfree(split_sizes);
-
        /* Grab a big lock for a long time to avoid concurrency issues */
        mutex_lock(&queue->queuelock);
 
@@ -829,13 +822,13 @@ static int sec_alg_skcipher_crypto(struct skcipher_request *skreq,
             (!queue->havesoftqueue ||
              kfifo_avail(&queue->softqueue) > steps)) ||
            !list_empty(&ctx->backlog)) {
+               ret = -EBUSY;
                if ((skreq->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) {
                        list_add_tail(&sec_req->backlog_head, &ctx->backlog);
                        mutex_unlock(&queue->queuelock);
-                       return -EBUSY;
+                       goto out;
                }
 
-               ret = -EBUSY;
                mutex_unlock(&queue->queuelock);
                goto err_free_elements;
        }
@@ -844,7 +837,15 @@ static int sec_alg_skcipher_crypto(struct skcipher_request *skreq,
        if (ret)
                goto err_free_elements;
 
-       return -EINPROGRESS;
+       ret = -EINPROGRESS;
+out:
+       /* Cleanup - all elements in pointer arrays have been copied */
+       kfree(splits_in_nents);
+       kfree(splits_in);
+       kfree(splits_out_nents);
+       kfree(splits_out);
+       kfree(split_sizes);
+       return ret;
 
 err_free_elements:
        list_for_each_entry_safe(el, temp, &sec_req->elements, head) {