1From 5057761e30e3a7682edab60f98f631616392ddc6 Mon Sep 17 00:00:00 2001
2From: Chrostoper Ertl <chertl@microsoft.com>
3Date: Thu, 28 Nov 2019 16:56:38 +0000
4Subject: [PATCH 3/3] channel: Fix buffer overflow
5MIME-Version: 1.0
6Content-Type: text/plain; charset=UTF-8
7Content-Transfer-Encoding: 8bit
8
9Partial fix for CVE-2020-5208, see
10https://github.com/ipmitool/ipmitool/security/advisories/GHSA-g659-9qxw-p7cp
11
12The `ipmi_get_channel_cipher_suites` function does not properly check
13the final response’s `data_len`, which can lead to stack buffer overflow
14on the final copy.
15
16Upstream-Status: Backport[https://github.com/ipmitool/ipmitool/commit/9452be87181a6e83cfcc768b3ed8321763db50e4]
17CVE: CVE-2020-5208
18
19[Make some changes to apply it]
20Signed-off-by: Wenlin Kang <wenlin.kang@windriver.com>
21---
22 include/ipmitool/ipmi_channel.h |  2 ++
23 lib/ipmi_channel.c              | 10 ++++++++--
24 2 files changed, 10 insertions(+), 2 deletions(-)
25
26diff --git a/include/ipmitool/ipmi_channel.h b/include/ipmitool/ipmi_channel.h
27index b138c26..d7cce5e 100644
28--- a/include/ipmitool/ipmi_channel.h
29+++ b/include/ipmitool/ipmi_channel.h
30@@ -77,6 +77,8 @@ struct channel_access_t {
31 	uint8_t user_level_auth;
32 };
33
34+#define MAX_CIPHER_SUITE_DATA_LEN 0x10
35+
36 /*
37  * The Get Authentication Capabilities response structure
38  * From table 22-15 of the IPMI v2.0 spec
39diff --git a/lib/ipmi_channel.c b/lib/ipmi_channel.c
40index fab2e54..76ecdcd 100644
41--- a/lib/ipmi_channel.c
42+++ b/lib/ipmi_channel.c
43@@ -378,7 +378,10 @@ ipmi_get_channel_cipher_suites(struct ipmi_intf *intf, const char *payload_type,
44 		lprintf(LOG_ERR, "Unable to Get Channel Cipher Suites");
45 		return -1;
46 	}
47-	if (rsp->ccode > 0) {
48+	if (rsp->ccode
49+	    || rsp->data_len < 1
50+	    || rsp->data_len > sizeof(uint8_t) + MAX_CIPHER_SUITE_DATA_LEN)
51+	{
52 		lprintf(LOG_ERR, "Get Channel Cipher Suites failed: %s",
53 			val2str(rsp->ccode, completion_code_vals));
54 		return -1;
55@@ -413,7 +416,10 @@ ipmi_get_channel_cipher_suites(struct ipmi_intf *intf, const char *payload_type,
56 			lprintf(LOG_ERR, "Unable to Get Channel Cipher Suites");
57 			return -1;
58 		}
59-		if (rsp->ccode > 0) {
60+		if (rsp->ccode
61+		    || rsp->data_len < 1
62+		    || rsp->data_len > sizeof(uint8_t) + MAX_CIPHER_SUITE_DATA_LEN)
63+		{
64 			lprintf(LOG_ERR, "Get Channel Cipher Suites failed: %s",
65 					val2str(rsp->ccode, completion_code_vals));
66 			return -1;
67--
682.18.1
69
70