1From 26e64ca78ae844c5ceedde89531e2924d7d4594c Mon Sep 17 00:00:00 2001 2From: Chrostoper Ertl <chertl@microsoft.com> 3Date: Thu, 28 Nov 2019 17:13:45 +0000 4Subject: [PATCH 5/5] fru, sdr: Fix id_string buffer overflows 5 6Final part of the fixes for CVE-2020-5208, see 7https://github.com/ipmitool/ipmitool/security/advisories/GHSA-g659-9qxw-p7cp 8 99 variants of stack buffer overflow when parsing `id_string` field of 10SDR records returned from `CMD_GET_SDR` command. 11 12SDR record structs have an `id_code` field, and an `id_string` `char` 13array. 14 15The length of `id_string` is calculated as `(id_code & 0x1f) + 1`, 16which can be larger than expected 16 characters (if `id_code = 0xff`, 17then length will be `(0xff & 0x1f) + 1 = 32`). 18 19In numerous places, this can cause stack buffer overflow when copying 20into fixed buffer of size `17` bytes from this calculated length. 21 22Upstream-Status: Backport[https://github.com/ipmitool/ipmitool/commit/7ccea283dd62a05a320c1921e3d8d71a87772637] 23CVE: CVE-2020-5208 24 25Signed-off-by: Wenlin Kang <wenlin.kang@windriver.com> 26--- 27 lib/ipmi_fru.c | 2 +- 28 lib/ipmi_sdr.c | 40 ++++++++++++++++++++++++---------------- 29 2 files changed, 25 insertions(+), 17 deletions(-) 30 31diff --git a/lib/ipmi_fru.c b/lib/ipmi_fru.c 32index b71ea23..1decea2 100644 33--- a/lib/ipmi_fru.c 34+++ b/lib/ipmi_fru.c 35@@ -3038,7 +3038,7 @@ ipmi_fru_print(struct ipmi_intf * intf, struct sdr_record_fru_locator * fru) 36 return 0; 37 38 memset(desc, 0, sizeof(desc)); 39- memcpy(desc, fru->id_string, fru->id_code & 0x01f); 40+ memcpy(desc, fru->id_string, __min(fru->id_code & 0x01f, sizeof(desc))); 41 desc[fru->id_code & 0x01f] = 0; 42 printf("FRU Device Description : %s (ID %d)\n", desc, fru->device_id); 43 44diff --git a/lib/ipmi_sdr.c b/lib/ipmi_sdr.c 45index fa7b082..175a86f 100644 46--- a/lib/ipmi_sdr.c 47+++ b/lib/ipmi_sdr.c 48@@ -2113,7 +2113,7 @@ ipmi_sdr_print_sensor_eventonly(struct ipmi_intf *intf, 49 return -1; 50 51 memset(desc, 0, sizeof (desc)); 52- snprintf(desc, (sensor->id_code & 0x1f) + 1, "%s", sensor->id_string); 53+ snprintf(desc, sizeof(desc), "%.*s", (sensor->id_code & 0x1f) + 1, sensor->id_string); 54 55 if (verbose) { 56 printf("Sensor ID : %s (0x%x)\n", 57@@ -2164,7 +2164,7 @@ ipmi_sdr_print_sensor_mc_locator(struct ipmi_intf *intf, 58 return -1; 59 60 memset(desc, 0, sizeof (desc)); 61- snprintf(desc, (mc->id_code & 0x1f) + 1, "%s", mc->id_string); 62+ snprintf(desc, sizeof(desc), "%.*s", (mc->id_code & 0x1f) + 1, mc->id_string); 63 64 if (verbose == 0) { 65 if (csv_output) 66@@ -2257,7 +2257,7 @@ ipmi_sdr_print_sensor_generic_locator(struct ipmi_intf *intf, 67 char desc[17]; 68 69 memset(desc, 0, sizeof (desc)); 70- snprintf(desc, (dev->id_code & 0x1f) + 1, "%s", dev->id_string); 71+ snprintf(desc, sizeof(desc), "%.*s", (dev->id_code & 0x1f) + 1, dev->id_string); 72 73 if (!verbose) { 74 if (csv_output) 75@@ -2314,7 +2314,7 @@ ipmi_sdr_print_sensor_fru_locator(struct ipmi_intf *intf, 76 char desc[17]; 77 78 memset(desc, 0, sizeof (desc)); 79- snprintf(desc, (fru->id_code & 0x1f) + 1, "%s", fru->id_string); 80+ snprintf(desc, sizeof(desc), "%.*s", (fru->id_code & 0x1f) + 1, fru->id_string); 81 82 if (!verbose) { 83 if (csv_output) 84@@ -2518,35 +2518,43 @@ ipmi_sdr_print_name_from_rawentry(struct ipmi_intf *intf,uint16_t id, 85 86 int rc =0; 87 char desc[17]; 88+ const char *id_string; 89+ uint8_t id_code; 90 memset(desc, ' ', sizeof (desc)); 91 92 switch ( type) { 93 case SDR_RECORD_TYPE_FULL_SENSOR: 94 record.full = (struct sdr_record_full_sensor *) raw; 95- snprintf(desc, (record.full->id_code & 0x1f) +1, "%s", 96- (const char *)record.full->id_string); 97+ id_code = record.full->id_code; 98+ id_string = record.full->id_string; 99 break; 100+ 101 case SDR_RECORD_TYPE_COMPACT_SENSOR: 102 record.compact = (struct sdr_record_compact_sensor *) raw ; 103- snprintf(desc, (record.compact->id_code & 0x1f) +1, "%s", 104- (const char *)record.compact->id_string); 105+ id_code = record.compact->id_code; 106+ id_string = record.compact->id_string; 107 break; 108+ 109 case SDR_RECORD_TYPE_EVENTONLY_SENSOR: 110 record.eventonly = (struct sdr_record_eventonly_sensor *) raw ; 111- snprintf(desc, (record.eventonly->id_code & 0x1f) +1, "%s", 112- (const char *)record.eventonly->id_string); 113- break; 114+ id_code = record.eventonly->id_code; 115+ id_string = record.eventonly->id_string; 116+ break; 117+ 118 case SDR_RECORD_TYPE_MC_DEVICE_LOCATOR: 119 record.mcloc = (struct sdr_record_mc_locator *) raw ; 120- snprintf(desc, (record.mcloc->id_code & 0x1f) +1, "%s", 121- (const char *)record.mcloc->id_string); 122+ id_code = record.mcloc->id_code; 123+ id_string = record.mcloc->id_string; 124 break; 125+ 126 default: 127 rc = -1; 128- break; 129- } 130+ } 131+ if (!rc) { 132+ snprintf(desc, sizeof(desc), "%.*s", (id_code & 0x1f) + 1, id_string); 133+ } 134 135- lprintf(LOG_INFO, "ID: 0x%04x , NAME: %-16s", id, desc); 136+ lprintf(LOG_INFO, "ID: 0x%04x , NAME: %-16s", id, desc); 137 return rc; 138 } 139 140-- 1411.9.1 142 143