From 2a84669ea0d685b4a2ccb664fa3236ec5f19a80a Mon Sep 17 00:00:00 2001 From: Chrostoper Ertl Date: Thu, 28 Nov 2019 16:56:38 +0000 Subject: [PATCH 4/6] channel: Fix buffer overflow MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 --- 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; -- 2.23.0