Commit a2cb9cd6 authored by Ekansh Gupta's avatar Ekansh Gupta Committed by Greg Kroah-Hartman
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misc: fastrpc: Fix incorrect DMA mapping unmap request 



Scatterlist table is obtained during map create request and the same
table is used for DMA mapping unmap. In case there is any failure
while getting the sg_table, ERR_PTR is returned instead of sg_table.

When the map is getting freed, there is only a non-NULL check of
sg_table which will also be true in case failure was returned instead
of sg_table. This would result in improper unmap request. Add proper
check before setting map table to avoid bad unmap request.

Fixes: c68cfb71 ("misc: fastrpc: Add support for context Invoke method")
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarEkansh Gupta <quic_ekangupt@quicinc.com>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230811115643.38578-3-srinivas.kandagatla@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ada6c2d9

drivers/misc/fastrpc.c

+5 −3
Original line number Diff line number Diff line
@@ -757,6 +757,7 @@ static int fastrpc_map_create(struct fastrpc_user *fl, int fd, 
{

	struct fastrpc_session_ctx *sess = fl->sctx;

	struct fastrpc_map *map = NULL;

	struct sg_table *table;

	int err = 0;



	if (!fastrpc_map_lookup(fl, fd, ppmap, true))
@@ -784,11 +785,12 @@ static int fastrpc_map_create(struct fastrpc_user *fl, int fd, 
		goto attach_err;

	}



	map->table = dma_buf_map_attachment_unlocked(map->attach, DMA_BIDIRECTIONAL);

	if (IS_ERR(map->table)) {

		err = PTR_ERR(map->table);

	table = dma_buf_map_attachment_unlocked(map->attach, DMA_BIDIRECTIONAL);

	if (IS_ERR(table)) {

		err = PTR_ERR(table);

		goto map_err;

	}

	map->table = table;



	if (attr & FASTRPC_ATTR_SECUREMAP) {

		map->phys = sg_phys(map->table->sgl);