misc: fastrpc: Clean buffers on remote invocation failures

With current design, buffers and dma handles are not freed in case
of remote invocation failures returned from DSP. This could result
in buffer leakings and dma handle pointing to wrong memory in the
fastrpc kernel. Adding changes to clean buffers and dma handles
even when remote invocation to DSP returns failures.

Fixes: c68cfb71 ("misc: fastrpc: Add support for context Invoke method")
Cc: stable <stable@kernel.org>
Signed-off-by: Ekansh Gupta <quic_ekangupt@quicinc.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231013122007.174464-4-srinivas.kandagatla@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/fastrpc.c

@@ -1176,11 +1176,6 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl,  u32 kernel,
 		err = wait_for_completion_interruptible(&ctx->work);
 	}
 
-	if (err)
-		goto bail;
-
-	/* Check the response from remote dsp */
-	err = ctx->retval;
 	if (err)
 		goto bail;
 
@@ -1191,6 +1186,11 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl,  u32 kernel,
 	if (err)
 		goto bail;
 
+	/* Check the response from remote dsp */
+	err = ctx->retval;
+	if (err)
+		goto bail;
+
 bail:
 	if (err != -ERESTARTSYS && err != -ETIMEDOUT) {
 		/* We are done with this compute context */