Module Name: src
Committed By: taca
Date: Fri Nov 1 15:01:27 UTC 2019
Modified Files:
src/sys/arch/x86/x86: cpu_rng.c
Log Message:
Check CPU support of RDRAND before calling cpu_rng_rdrand().
cpu_earlyrng() checks CPU support of RDSEED and RDRAND before calling
cpu_rng_rdseed() and cpu_rng_rdrand().
But cpu_rng_rdseed() did not check CPU support of RDRAND and system had
crashed on such an environment. There is no such case with real CPU but
some VM environment.
Fix kern/54655 and confirmed by msaitoh@.
Needs pullup to netbsd-9.
To generate a diff of this commit:
cvs rdiff -u -r1.9 -r1.10 src/sys/arch/x86/x86/cpu_rng.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/x86/x86/cpu_rng.c
diff -u src/sys/arch/x86/x86/cpu_rng.c:1.9 src/sys/arch/x86/x86/cpu_rng.c:1.10
--- src/sys/arch/x86/x86/cpu_rng.c:1.9 Wed Aug 22 12:07:43 2018
+++ src/sys/arch/x86/x86/cpu_rng.c Fri Nov 1 15:01:27 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: cpu_rng.c,v 1.9 2018/08/22 12:07:43 maxv Exp $ */
+/* $NetBSD: cpu_rng.c,v 1.10 2019/11/01 15:01:27 taca Exp $ */
/*-
* Copyright (c) 2015 The NetBSD Foundation, Inc.
@@ -53,6 +53,8 @@ static enum {
CPU_RNG_VIA
} cpu_rng_mode __read_mostly = CPU_RNG_NONE;
+static bool has_rdrand;
+
bool
cpu_rng_init(void)
{
@@ -131,7 +133,10 @@ cpu_rng_rdseed(cpu_rng_t *out)
* to be seeded even in this case.
*/
exhausted:
- return cpu_rng_rdrand(out);
+ if (has_rdrand)
+ return cpu_rng_rdrand(out);
+ else
+ return 0;
}
static size_t
@@ -213,7 +218,7 @@ cpu_earlyrng(void *out, size_t sz)
int i;
bool has_rdseed = (cpu_feature[5] & CPUID_SEF_RDSEED) != 0;
- bool has_rdrand = (cpu_feature[1] & CPUID2_RDRAND) != 0;
+ has_rdrand = (cpu_feature[1] & CPUID2_RDRAND) != 0;
KASSERT(sz + sizeof(uint64_t) <= SHA512_DIGEST_LENGTH);
