Re: [dpdk-dev] [PATCH 2/2] eal/ipc: fix use-after-free in asynchronous requests

["Tan, Jianfeng" <jianfeng.tan@intel.com>]

On 4/13/2018 7:55 PM, Anatoly Burakov wrote:
> Previously, we were removing request from the list only if we
> have succeeded to send it. This resulted in leaving an invalid
> pointer in the request list.
>
> Fix this by only adding new requests to the request list if we
> have succeeded in sending them.
>
> Fixes: f05e26051c15 ("eal: add IPC asynchronous request")
> Cc: anatoly.burakov@intel.com
>
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>

Acked-by: Jianfeng Tan <jianfeng.tan@intel.com>

> ---
>   lib/librte_eal/common/eal_common_proc.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/lib/librte_eal/common/eal_common_proc.c b/lib/librte_eal/common/eal_common_proc.c
> index e3eb430..a8ca7b8 100644
> --- a/lib/librte_eal/common/eal_common_proc.c
> +++ b/lib/librte_eal/common/eal_common_proc.c
> @@ -876,9 +876,7 @@ mp_request_async(const char *dst, struct rte_mp_msg *req,
>   	/* queue already locked by caller */
>   
>   	exist = find_sync_request(dst, req->name);
> -	if (!exist) {
> -		TAILQ_INSERT_TAIL(&pending_requests.requests, sync_req, next);
> -	} else {
> +	if (exist) {
>   		RTE_LOG(ERR, EAL, "A pending request %s:%s\n", dst, req->name);
>   		rte_errno = EEXIST;
>   		ret = -1;
> @@ -895,6 +893,7 @@ mp_request_async(const char *dst, struct rte_mp_msg *req,
>   		ret = 0;
>   		goto fail;
>   	}
> +	TAILQ_INSERT_TAIL(&pending_requests.requests, sync_req, next);
>   
>   	param->user_reply.nb_sent++;
>