From 12fbde92a26da61eda9f2ff0ba3c316779163f10 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Fri, 20 Jan 2017 10:57:12 +0100 Subject: [PATCH 18/19] Only decode one DMI table Since version 3.0.0 of the SMBIOS specification, there can be multiple entry points in memory, pointing to one or two DMI tables. If both a 32-bit ("_SM_") entry point and a 64-bit ("_SM3_") entry point are present, the specification requires that the latter points to a table which is a super-set of the table pointed to by the former. Therefore it makes no sense to decode both. Per specification, look for a 64-bit ("_SM3_") entry point first, and if we can't find any, look for a 32-bit ("_SM_" or "_DMI_") entry point. This fixes bug #50022: https://savannah.nongnu.org/bugs/?50022 --- CHANGELOG | 6 ++++++ dmidecode.c | 19 ++++++++++++++----- 2 files changed, 20 insertions(+), 5 deletions(-) diff --git a/CHANGELOG b/CHANGELOG index ac748b0..67aef99 100644 --- a/CHANGELOG +++ b/CHANGELOG @@ -1,3 +1,9 @@ +2017-01-20 Jean Delvare + + * dmidecode.c: Only decode one DMI table. + This fixes Savannah bug #50022: + https://savannah.nongnu.org/bugs/?50022 + 2016-09-22 Jean Delvare * README: Explain that we can no longer support Cygwin. diff --git a/dmidecode.c b/dmidecode.c index 3993592..4b46a13 100644 --- a/dmidecode.c +++ b/dmidecode.c @@ -4925,28 +4925,37 @@ memory_scan: goto exit_free; } - for (fp = 0; fp <= 0xFFF0; fp += 16) + /* Look for a 64-bit entry point first */ + for (fp = 0; fp <= 0xFFE0; fp += 16) { - if (memcmp(buf + fp, "_SM3_", 5) == 0 && fp <= 0xFFE0) + if (memcmp(buf + fp, "_SM3_", 5) == 0) { if (smbios3_decode(buf + fp, opt.devmem, 0)) { found++; - fp += 16; + goto done; } } - else if (memcmp(buf + fp, "_SM_", 4) == 0 && fp <= 0xFFE0) + } + + /* If none found, look for a 32-bit entry point */ + for (fp = 0; fp <= 0xFFF0; fp += 16) + { + if (memcmp(buf + fp, "_SM_", 4) == 0 && fp <= 0xFFE0) { if (smbios_decode(buf + fp, opt.devmem, 0)) { found++; - fp += 16; + goto done; } } else if (memcmp(buf + fp, "_DMI_", 5) == 0) { if (legacy_decode(buf + fp, opt.devmem, 0)) + { found++; + goto done; + } } } -- 2.9.3