@@ -748,7 +748,8 @@ static int encode_message(struct qaic_device *qdev, struct manage_msg *user_msg,
int ret;
int i;
- if (!user_msg->count) {
+ if (!user_msg->count ||
+ user_msg->len < sizeof(*trans_hdr)) {
ret = -EINVAL;
goto out;
}
@@ -765,12 +766,13 @@ static int encode_message(struct qaic_device *qdev, struct manage_msg *user_msg,
}
for (i = 0; i < user_msg->count; ++i) {
- if (user_len >= user_msg->len) {
+ if (user_len >= user_msg->len - sizeof(*trans_hdr)) {
ret = -EINVAL;
break;
}
trans_hdr = (struct qaic_manage_trans_hdr *)(user_msg->data + user_len);
- if (user_len + trans_hdr->len > user_msg->len) {
+ if (trans_hdr->len < sizeof(trans_hdr) ||
+ size_add(user_len, trans_hdr->len) > user_msg->len) {
ret = -EINVAL;
break;
}
There are several issues in this code. The check at the start of the loop: if (user_len >= user_msg->len) { This check does not ensure that we have enough space for the trans_hdr (8 bytes). Instead the check needs to be: if (user_len >= user_msg->len - sizeof(*trans_hdr)) { That subtraction is done as an unsigned long we want to avoid negatives. Add a lower bound to the start of the function. if (user_msg->len < sizeof(*trans_hdr)) There is a second integer underflow which can happen if trans_hdr->len is zero inside the encode_passthrough() function. memcpy(out_trans->data, in_trans->data, in_trans->hdr.len - sizeof(in_trans->hdr)); Instead of adding a check to encode_passthrough() it's better to check in this central place. Add that check: if (trans_hdr->len < sizeof(trans_hdr) The final concern is that the "user_len + trans_hdr->len" might have an integer overflow bug. Use size_add() to prevent that. - if (user_len + trans_hdr->len > user_msg->len) { + if (size_add(user_len, trans_hdr->len) > user_msg->len) { Fixes: 129776ac2e38 ("accel/qaic: Add control path") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> --- This is based on code review and not tested. drivers/accel/qaic/qaic_control.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)