Re: [PATCH v2] misc: fastrpc: fix potential fastrpc_invoke_ctx leak
From: Bjorn Andersson
Date: Tue May 12 2020 - 13:30:53 EST
On Tue 12 May 04:09 PDT 2020, Srinivas Kandagatla wrote:
> fastrpc_invoke_ctx can have refcount of 2 in error path where
> rpmsg_send() fails to send invoke message. decrement the refcount
> properly in the error path to fix this leak.
>
> This also fixes below static checker warning:
>
> drivers/misc/fastrpc.c:990 fastrpc_internal_invoke()
> warn: 'ctx->refcount.refcount.ref.counter' not decremented on lines: 990.
>
> Fixes: c68cfb718c8f ("misc: fastrpc: Add support for context")
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Thanks, that looks better.
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Regards,
Bjorn
> ---
> Changes since v1:
> moved fastrpc_context_put to fastrpc_invoke_send()
>
> drivers/misc/fastrpc.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> index 9065d3e71ff7..7939c55daceb 100644
> --- a/drivers/misc/fastrpc.c
> +++ b/drivers/misc/fastrpc.c
> @@ -904,6 +904,7 @@ static int fastrpc_invoke_send(struct fastrpc_session_ctx *sctx,
> struct fastrpc_channel_ctx *cctx;
> struct fastrpc_user *fl = ctx->fl;
> struct fastrpc_msg *msg = &ctx->msg;
> + int ret;
>
> cctx = fl->cctx;
> msg->pid = fl->tgid;
> @@ -919,7 +920,13 @@ static int fastrpc_invoke_send(struct fastrpc_session_ctx *sctx,
> msg->size = roundup(ctx->msg_sz, PAGE_SIZE);
> fastrpc_context_get(ctx);
>
> - return rpmsg_send(cctx->rpdev->ept, (void *)msg, sizeof(*msg));
> + ret = rpmsg_send(cctx->rpdev->ept, (void *)msg, sizeof(*msg));
> +
> + if (ret)
> + fastrpc_context_put(ctx);
> +
> + return ret;
> +
> }
>
> static int fastrpc_internal_invoke(struct fastrpc_user *fl, u32 kernel,
> --
> 2.21.0
>