The second byte of the GET_STRING_ATTRIB report is a length, so we should set
the size of the buffer to be the size we're actually requesting, and only
reject the reply if the length out is nonsensical.
Signed-off-by: Vicki Pfau <vi@xxxxxxxxxxx>
---
drivers/hid/hid-steam.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/hid/hid-steam.c b/drivers/hid/hid-steam.c
index 4f5c647f04dd..a0ed8812e7ea 100644
--- a/drivers/hid/hid-steam.c
+++ b/drivers/hid/hid-steam.c
@@ -274,7 +274,7 @@ enum {
};
/* Other random constants */
-#define STEAM_SERIAL_LEN 10
+#define STEAM_SERIAL_LEN 0x15
struct steam_device {
struct list_head list;
@@ -421,10 +421,10 @@ static int steam_get_serial(struct steam_device *steam)
{
/*
* Send: 0xae 0x15 0x01
- * Recv: 0xae 0x15 0x01 serialnumber (10 chars)
+ * Recv: 0xae 0x15 0x01 serialnumber
*/
int ret = 0;
- u8 cmd[] = {ID_GET_STRING_ATTRIBUTE, 0x15, ATTRIB_STR_UNIT_SERIAL};
+ u8 cmd[] = {ID_GET_STRING_ATTRIBUTE, sizeof(steam->serial_no), ATTRIB_STR_UNIT_SERIAL};
u8 reply[3 + STEAM_SERIAL_LEN + 1];
mutex_lock(&steam->report_mutex);
@@ -434,12 +434,13 @@ static int steam_get_serial(struct steam_device *steam)
ret = steam_recv_report(steam, reply, sizeof(reply));
if (ret < 0)
goto out;
- if (reply[0] != ID_GET_STRING_ATTRIBUTE || reply[1] != 0x15 || reply[2] != ATTRIB_STR_UNIT_SERIAL) {
+ if (reply[0] != ID_GET_STRING_ATTRIBUTE || reply[1] < 1 ||
+ reply[1] > sizeof(steam->serial_no) || reply[2] != ATTRIB_STR_UNIT_SERIAL) {
ret = -EIO;
goto out;
}
reply[3 + STEAM_SERIAL_LEN] = 0;
- strscpy(steam->serial_no, reply + 3, sizeof(steam->serial_no));
+ strscpy(steam->serial_no, reply + 3, reply[1]);
out:
mutex_unlock(&steam->report_mutex);
return ret;
--
2.42.0
