From 5057761e30e3a7682edab60f98f631616392ddc6 Mon Sep 17 00:00:00 2001
From: Chrostoper Ertl <chertl@microsoft.com>
Date: Thu, 28 Nov 2019 16:56:38 +0000
Subject: [PATCH 3/3] channel: Fix buffer overflow
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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.

Upstream-Status: Backport[https://github.com/ipmitool/ipmitool/commit/9452be87181a6e83cfcc768b3ed8321763db50e4]
CVE: CVE-2020-5208

[Make some changes to apply it]
Signed-off-by: Wenlin Kang <wenlin.kang@windriver.com>
---
 include/ipmitool/ipmi_channel.h |  2 ++
 lib/ipmi_channel.c              | 10 ++++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/ipmitool/ipmi_channel.h b/include/ipmitool/ipmi_channel.h
index b138c26..d7cce5e 100644
--- a/include/ipmitool/ipmi_channel.h
+++ b/include/ipmitool/ipmi_channel.h
@@ -77,6 +77,8 @@ struct channel_access_t {
 	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
diff --git a/lib/ipmi_channel.c b/lib/ipmi_channel.c
index fab2e54..76ecdcd 100644
--- a/lib/ipmi_channel.c
+++ b/lib/ipmi_channel.c
@@ -378,7 +378,10 @@ ipmi_get_channel_cipher_suites(struct ipmi_intf *intf, const char *payload_type,
 		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;
@@ -413,7 +416,10 @@ ipmi_get_channel_cipher_suites(struct ipmi_intf *intf, const char *payload_type,
 			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;
-- 
2.18.1