accel/qaic: Fix integer overflow in qaic_validate_req()

These are u64 variables that come from the user via
qaic_attach_slice_bo_ioctl().  Use check_add_overflow() to ensure that
the math doesn't have an integer wrapping bug.

Cc: stable@vger.kernel.org
Fixes: ff13be8 ("accel/qaic: Add datapath")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Signed-off-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/176388fa-40fe-4cb4-9aeb-2c91c22130bd@stanley.mountain

drivers/accel/qaic/qaic_data.c

@@ -557,6 +557,7 @@ static bool invalid_sem(struct qaic_sem *sem)
 static int qaic_validate_req(struct qaic_device *qdev, struct qaic_attach_slice_entry *slice_ent,
 			     u32 count, u64 total_size)
 {
+	u64 total;
 	int i;
 
 	for (i = 0; i < count; i++) {
@@ -566,7 +567,8 @@ static int qaic_validate_req(struct qaic_device *qdev, struct qaic_attach_slice_
 		      invalid_sem(&slice_ent[i].sem2) || invalid_sem(&slice_ent[i].sem3))
 			return -EINVAL;
 
-		if (slice_ent[i].offset + slice_ent[i].size > total_size)
+		if (check_add_overflow(slice_ent[i].offset, slice_ent[i].size, &total) ||
+		    total > total_size)
 			return -EINVAL;
 	}