[PATCH 5.15 169/171] misc: fastrpc: fix improper packet size calculation

Greg Kroah-Hartman
2021-12-13T10:08:06Z

From: Jeya R <jeyr@codeaurora.org>

commit 3a1bf591e9a410f220b7405a142a47407394a1d5 upstream.

The buffer list is sorted and this is not being considered while
calculating packet size. This would lead to improper copy length
calculation for non-dmaheap buffers which would eventually cause
sending improper buffers to DSP.

Fixes: c68cfb718c8f ("misc: fastrpc: Add support for context Invoke method")
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Jeya R <jeyr@codeaurora.org>
Link: https://lore.kernel.org/r/1637771481-4299-1-git-send-email-jeyr@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/misc/fastrpc.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -719,16 +719,18 @@ static int fastrpc_get_meta_size(struct
static u64 fastrpc_get_payload_size(struct fastrpc_invoke_ctx *ctx, int metalen)
{
u64 size = 0;
- int i;
+ int oix;

size = ALIGN(metalen, FASTRPC_ALIGN);
- for (i = 0; i < ctx->nscalars; i++) {
+ for (oix = 0; oix < ctx->nbufs; oix++) {
+ int i = ctx->olaps[oix].raix;
+
if (ctx->args[i].fd == 0 || ctx->args[i].fd == -1) {

- if (ctx->olaps[i].offset == 0)
+ if (ctx->olaps[oix].offset == 0)
size = ALIGN(size, FASTRPC_ALIGN);

- size += (ctx->olaps[i].mend - ctx->olaps[i].mstart);
+ size += (ctx->olaps[oix].mend - ctx->olaps[oix].mstart);
}
}