From 37ba3c350e64adcbdd483e81bf194c05d9573515 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Sat, 14 Apr 2018 17:06:44 +0200
Subject: [PATCH] HID: intel_ish-hid: Move header size check to inside the loop
Git-commit: 37ba3c350e64adcbdd483e81bf194c05d9573515
Patch-mainline: v4.17-rc5
References: jsc#SLE-5241
With the headersize check outside of the loop, the second time through
the loop the: "payload_len = recv_msg->hdr.size;" statement may deref
recv_msg while it is pointing outside of our input buffer.
Move the headersize check to inside the loop to fix this.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/hid/intel-ish-hid/ishtp-hid-client.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/hid/intel-ish-hid/ishtp-hid-client.c b/drivers/hid/intel-ish-hid/ishtp-hid-client.c
index 157b44aacdff..6ce1856bb368 100644
--- a/drivers/hid/intel-ish-hid/ishtp-hid-client.c
+++ b/drivers/hid/intel-ish-hid/ishtp-hid-client.c
@@ -77,21 +77,21 @@ static void process_recv(struct ishtp_cl *hid_ishtp_cl, void *recv_buf,
struct ishtp_cl_data *client_data = hid_ishtp_cl->client_data;
int curr_hid_dev = client_data->cur_hid_dev;
- if (data_len < sizeof(struct hostif_msg_hdr)) {
- dev_err(&client_data->cl_device->dev,
- "[hid-ish]: error, received %u which is less than data header %u\n",
- (unsigned int)data_len,
- (unsigned int)sizeof(struct hostif_msg_hdr));
- ++client_data->bad_recv_cnt;
- ish_hw_reset(hid_ishtp_cl->dev);
- return;
- }
-
payload = recv_buf + sizeof(struct hostif_msg_hdr);
total_len = data_len;
cur_pos = 0;
do {
+ if (cur_pos + sizeof(struct hostif_msg) > total_len) {
+ dev_err(&client_data->cl_device->dev,
+ "[hid-ish]: error, received %u which is less than data header %u\n",
+ (unsigned int)data_len,
+ (unsigned int)sizeof(struct hostif_msg_hdr));
+ ++client_data->bad_recv_cnt;
+ ish_hw_reset(hid_ishtp_cl->dev);
+ break;
+ }
+
recv_msg = (struct hostif_msg *)(recv_buf + cur_pos);
payload_len = recv_msg->hdr.size;
--
2.16.4