[PATCH v2 1/2] media: venus: fix OOB read issue due to double read

[Vedang Nagar]

During message queue read, the address is being read twice
from the shared memory. The first read is validated against
the size of the packet, however the second read is not
being validated. Therefore, it's possible for firmware to
modify the value to a bigger invalid value which can lead
to OOB read access issue while reading the packet.
Added fix to reupdate the size of the packet which was
read for the first time.

Signed-off-by: Vedang Nagar <quic_vnagar@xxxxxxxxxxx>
---
 drivers/media/platform/qcom/venus/hfi_venus.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/media/platform/qcom/venus/hfi_venus.c b/drivers/media/platform/qcom/venus/hfi_venus.c
index f9437b6412b91c2483670a2b11f4fd43f3206404..c124db8ac79d18f32289a690ee82145dc93daee6 100644
--- a/drivers/media/platform/qcom/venus/hfi_venus.c
+++ b/drivers/media/platform/qcom/venus/hfi_venus.c
@@ -298,6 +298,7 @@ static int venus_read_queue(struct venus_hfi_device *hdev,
 			memcpy(pkt, rd_ptr, len);
 			memcpy(pkt + len, queue->qmem.kva, new_rd_idx << 2);
 		}
+		*(u32 *)pkt = dwords << 2;
 	} else {
 		/* bad packet received, dropping */
 		new_rd_idx = qhdr->write_idx;

-- 
2.34.1