arch/x86/smbios: Fix undefined behavior
Fixes report found by undefined behavior sanitizer. Dereferencing a
pointer that's not aligned to the size of access is undefined behavior.
The report triggered for smbios_cpu_vendor(). Also fixes the same issue
in smbios_processor_name() found by inspection.
Change-Id: I1b7d08655edce729e107a5b6e61ee509ebde33b6
Signed-off-by: Ryan Salsamendi <rsalsamendi@hotmail.com>
Reviewed-on: https://review.coreboot.org/20154
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>
diff --git a/src/arch/x86/smbios.c b/src/arch/x86/smbios.c
index 0909900..2bbf3c9 100644
--- a/src/arch/x86/smbios.c
+++ b/src/arch/x86/smbios.c
@@ -86,42 +86,40 @@
static int smbios_cpu_vendor(char *start)
{
- char tmp[13] = "Unknown";
- u32 *_tmp = (u32 *)tmp;
- struct cpuid_result res;
-
if (cpu_have_cpuid()) {
- res = cpuid(0);
- _tmp[0] = res.ebx;
- _tmp[1] = res.edx;
- _tmp[2] = res.ecx;
- tmp[12] = '\0';
+ u32 tmp[4];
+ const struct cpuid_result res = cpuid(0);
+ tmp[0] = res.ebx;
+ tmp[1] = res.edx;
+ tmp[2] = res.ecx;
+ tmp[3] = 0;
+ return smbios_add_string(start, (const char *)tmp);
+ } else {
+ return smbios_add_string(start, "Unknown");
}
-
- return smbios_add_string(start, tmp);
}
static int smbios_processor_name(char *start)
{
- char tmp[49] = "Unknown Processor Name";
- u32 *_tmp = (u32 *)tmp;
- struct cpuid_result res;
- int i;
-
+ const char *str = "Unknown Processor Name";
if (cpu_have_cpuid()) {
- res = cpuid(0x80000000);
+ int i;
+ struct cpuid_result res = cpuid(0x80000000);
if (res.eax >= 0x80000004) {
+ u32 tmp[13];
+ int j = 0;
for (i = 0; i < 3; i++) {
res = cpuid(0x80000002 + i);
- _tmp[i * 4 + 0] = res.eax;
- _tmp[i * 4 + 1] = res.ebx;
- _tmp[i * 4 + 2] = res.ecx;
- _tmp[i * 4 + 3] = res.edx;
+ tmp[j++] = res.eax;
+ tmp[j++] = res.ebx;
+ tmp[j++] = res.ecx;
+ tmp[j++] = res.edx;
}
- tmp[48] = 0;
+ tmp[12] = 0;
+ str = (const char *)tmp;
}
}
- return smbios_add_string(start, tmp);
+ return smbios_add_string(start, str);
}
/* this function will fill the corresponding manufacturer */