On Mon, Jun 22, 2020 at 04:35:46PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> kzalloc failures return NULL on out of memory errors, so replace the
> IS_ERR_OR_NULL check with the usual null pointer check. Fix two memory
> leaks with on acomp and acomp_ctx by ensuring these objects are free'd
> on the error return path.
>
> Addresses-Coverity: ("Resource leak")
> Fixes: d4f86abd6e35 ("mm/zswap: move to use crypto_acomp API for hardware acceleration")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
> mm/zswap.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/mm/zswap.c b/mm/zswap.c
> index 0d914ba6b4a0..14839cbac7ff 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -433,23 +433,23 @@ static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node)
> return 0;
>
> acomp_ctx = kzalloc(sizeof(*acomp_ctx), GFP_KERNEL);
> - if (IS_ERR_OR_NULL(acomp_ctx)) {
> + if (!acomp_ctx) {
> pr_err("Could not initialize acomp_ctx\n");
> return -ENOMEM;
> }
> acomp = crypto_alloc_acomp(pool->tfm_name, 0, 0);
> - if (IS_ERR_OR_NULL(acomp)) {
> + if (!acomp) {
This should be IS_ERR(acomp). Please preserve the error code.
> pr_err("could not alloc crypto acomp %s : %ld\n",
> pool->tfm_name, PTR_ERR(acomp));
> - return -ENOMEM;
> + goto free_acomp_ctx;
> }
> acomp_ctx->acomp = acomp;
>
> req = acomp_request_alloc(acomp_ctx->acomp);
> - if (IS_ERR_OR_NULL(req)) {
> + if (!req) {
> pr_err("could not alloc crypto acomp %s : %ld\n",
> pool->tfm_name, PTR_ERR(acomp));
> - return -ENOMEM;
> + goto free_acomp;
> }
> acomp_ctx->req = req;
>
> @@ -462,6 +462,12 @@ static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node)
> *per_cpu_ptr(pool->acomp_ctx, cpu) = acomp_ctx;
>
> return 0;
> +
> +free_acomp:
> + kfree(acomp);
The kfree() isn't correct. It needs to be:
crypto_free_acomp(acomp);
> +free_acomp_ctx:
> + kfree(acomp_ctx);
> + return -ENOMEM;
regards,
dan carpenter
