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crypto: hisilicon - Fix reference after free of memories on error path
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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: 915e4e8 ("crypto: hisilicon - SEC security accelerator driver")
Reviewed-by: Jonathan Cameron <[email protected]>
Cc: <[email protected]>
Signed-off-by: John Garry <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
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John Garry authored and herbertx committed Nov 9, 2018
1 parent 68a031d commit 0b0cf6a
Showing 1 changed file with 11 additions and 10 deletions.
21 changes: 11 additions & 10 deletions drivers/crypto/hisilicon/sec/sec_algs.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);

Expand All @@ -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;
}
Expand All @@ -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) {
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