Subject: [PATCH 4/6] channel: Fix buffer overflow
 Partial fix for CVE-2020-5208, see
 https://github.com/ipmitool/ipmitool/security/advisories/GHSA-g659-9qxw-p7cp
 .
 The `ipmi_get_channel_cipher_suites` function does not properly check
 the final response’s `data_len`, which can lead to stack buffer overflow
 on the final copy.
 From 9452be87181a6e83cfcc768b3ed8321763db50e4 Mon Sep 17 00:00:00 2001
From: Chrostoper Ertl <chertl@microsoft.com>
Date: Thu, 28 Nov 2019 16:56:38 +0000
Last-Update: 2021-02-08

--- ipmitool-1.8.18.orig/lib/ipmi_channel.c
+++ ipmitool-1.8.18/lib/ipmi_channel.c
@@ -413,7 +413,10 @@ ipmi_get_channel_cipher_suites(struct ip
 			lprintf(LOG_ERR, "Unable to Get Channel Cipher Suites");
 			return -1;
 		}
-		if (rsp->ccode > 0) {
+		if (rsp->ccode
+			|| rsp->data_len < 1
+			|| rsp->data_len > sizeof(uint8_t) + MAX_CIPHER_SUITE_DATA_LEN)
+		{
 			lprintf(LOG_ERR, "Get Channel Cipher Suites failed: %s",
 					val2str(rsp->ccode, completion_code_vals));
 			return -1;
--- a/include/ipmitool/ipmi_channel.h	2016-05-29 21:46:53.000000000 +0200
+++ b/include/ipmitool/ipmi_channel.h	2021-02-08 23:45:10.598535426 +0100
@@ -77,6 +77,8 @@
 	uint8_t user_level_auth;
 };
 
+#define MAX_CIPHER_SUITE_DATA_LEN 0x10
+
 /*
  * The Get Authentication Capabilities response structure
  * From table 22-15 of the IPMI v2.0 spec