[PATCH v2 1/4] venus: hfi: add checks to perform sanity on queue pointers

[Vikash Garodia]

Read and write pointers are used to track the packet index in the memory
shared between video driver and firmware. There is a possibility of OOB
access if the read or write pointer goes beyond the queue memory size.
Add checks for the read and write pointer to avoid OOB access.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: d96d3f30c0f2 ("[media] media: venus: hfi: add Venus HFI files")
Signed-off-by: Vikash Garodia <quic_vgarodia@xxxxxxxxxxx>
---
 drivers/media/platform/qcom/venus/hfi_venus.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/media/platform/qcom/venus/hfi_venus.c b/drivers/media/platform/qcom/venus/hfi_venus.c
index f0b4638..4ddabb1 100644
--- a/drivers/media/platform/qcom/venus/hfi_venus.c
+++ b/drivers/media/platform/qcom/venus/hfi_venus.c
@@ -206,6 +206,11 @@ static int venus_write_queue(struct venus_hfi_device *hdev,
 
 	new_wr_idx = wr_idx + dwords;
 	wr_ptr = (u32 *)(queue->qmem.kva + (wr_idx << 2));
+
+	if (wr_ptr < (u32 *)queue->qmem.kva ||
+	    wr_ptr > (u32 *)(queue->qmem.kva + queue->qmem.size - sizeof(*wr_ptr)))
+		return -EINVAL;
+
 	if (new_wr_idx < qsize) {
 		memcpy(wr_ptr, packet, dwords << 2);
 	} else {
@@ -273,6 +278,11 @@ static int venus_read_queue(struct venus_hfi_device *hdev,
 	}
 
 	rd_ptr = (u32 *)(queue->qmem.kva + (rd_idx << 2));
+
+	if (rd_ptr < (u32 *)queue->qmem.kva ||
+	    rd_ptr > (u32 *)(queue->qmem.kva + queue->qmem.size - sizeof(*rd_ptr)))
+		return -EINVAL;
+
 	dwords = *rd_ptr >> 2;
 	if (!dwords)
 		return -EINVAL;
-- 
2.7.4