Skip to content

Commit

Permalink
Merge pull request #3300 from markusboehme/fix/cve-2023-20593-zenbleed
Browse files Browse the repository at this point in the history
Cherry-pick fix for CVE-2023-20593 ("Zenbleed")
  • Loading branch information
markusboehme authored Jul 27, 2023
2 parents 50e0b8c + 512b5c4 commit edf01e2
Show file tree
Hide file tree
Showing 9 changed files with 1,083 additions and 0 deletions.
Original file line number Diff line number Diff line change
@@ -0,0 +1,184 @@
From 191b8f9b0e3708e8325d8d28e1005a1fbe5e3991 Mon Sep 17 00:00:00 2001
From: "Borislav Petkov (AMD)" <[email protected]>
Date: Sat, 15 Jul 2023 13:31:32 +0200
Subject: [PATCH] x86/cpu/amd: Move the errata checking functionality up

Upstream commit: 8b6f687743dacce83dbb0c7cfacf88bab00f808a

Avoid new and remove old forward declarations.

No functional changes.

Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/x86/kernel/cpu/amd.c | 139 ++++++++++++++++++--------------------
1 file changed, 67 insertions(+), 72 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 89a9b7754476..6eea37f827b1 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -28,11 +28,6 @@

#include "cpu.h"

-static const int amd_erratum_383[];
-static const int amd_erratum_400[];
-static const int amd_erratum_1054[];
-static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum);
-
/*
* nodes_per_socket: Stores the number of nodes per socket.
* Refer to Fam15h Models 00-0fh BKDG - CPUID Fn8000_001E_ECX
@@ -40,6 +35,73 @@ static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum);
*/
static u32 nodes_per_socket = 1;

+/*
+ * AMD errata checking
+ *
+ * Errata are defined as arrays of ints using the AMD_LEGACY_ERRATUM() or
+ * AMD_OSVW_ERRATUM() macros. The latter is intended for newer errata that
+ * have an OSVW id assigned, which it takes as first argument. Both take a
+ * variable number of family-specific model-stepping ranges created by
+ * AMD_MODEL_RANGE().
+ *
+ * Example:
+ *
+ * const int amd_erratum_319[] =
+ * AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0x4, 0x2),
+ * AMD_MODEL_RANGE(0x10, 0x8, 0x0, 0x8, 0x0),
+ * AMD_MODEL_RANGE(0x10, 0x9, 0x0, 0x9, 0x0));
+ */
+
+#define AMD_LEGACY_ERRATUM(...) { -1, __VA_ARGS__, 0 }
+#define AMD_OSVW_ERRATUM(osvw_id, ...) { osvw_id, __VA_ARGS__, 0 }
+#define AMD_MODEL_RANGE(f, m_start, s_start, m_end, s_end) \
+ ((f << 24) | (m_start << 16) | (s_start << 12) | (m_end << 4) | (s_end))
+#define AMD_MODEL_RANGE_FAMILY(range) (((range) >> 24) & 0xff)
+#define AMD_MODEL_RANGE_START(range) (((range) >> 12) & 0xfff)
+#define AMD_MODEL_RANGE_END(range) ((range) & 0xfff)
+
+static const int amd_erratum_400[] =
+ AMD_OSVW_ERRATUM(1, AMD_MODEL_RANGE(0xf, 0x41, 0x2, 0xff, 0xf),
+ AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0xff, 0xf));
+
+static const int amd_erratum_383[] =
+ AMD_OSVW_ERRATUM(3, AMD_MODEL_RANGE(0x10, 0, 0, 0xff, 0xf));
+
+/* #1054: Instructions Retired Performance Counter May Be Inaccurate */
+static const int amd_erratum_1054[] =
+ AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x17, 0, 0, 0x2f, 0xf));
+
+static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum)
+{
+ int osvw_id = *erratum++;
+ u32 range;
+ u32 ms;
+
+ if (osvw_id >= 0 && osvw_id < 65536 &&
+ cpu_has(cpu, X86_FEATURE_OSVW)) {
+ u64 osvw_len;
+
+ rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, osvw_len);
+ if (osvw_id < osvw_len) {
+ u64 osvw_bits;
+
+ rdmsrl(MSR_AMD64_OSVW_STATUS + (osvw_id >> 6),
+ osvw_bits);
+ return osvw_bits & (1ULL << (osvw_id & 0x3f));
+ }
+ }
+
+ /* OSVW unavailable or ID unknown, match family-model-stepping range */
+ ms = (cpu->x86_model << 4) | cpu->x86_stepping;
+ while ((range = *erratum++))
+ if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range)) &&
+ (ms >= AMD_MODEL_RANGE_START(range)) &&
+ (ms <= AMD_MODEL_RANGE_END(range)))
+ return true;
+
+ return false;
+}
+
static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
{
u32 gprs[8] = { 0 };
@@ -1153,73 +1215,6 @@ static const struct cpu_dev amd_cpu_dev = {

cpu_dev_register(amd_cpu_dev);

-/*
- * AMD errata checking
- *
- * Errata are defined as arrays of ints using the AMD_LEGACY_ERRATUM() or
- * AMD_OSVW_ERRATUM() macros. The latter is intended for newer errata that
- * have an OSVW id assigned, which it takes as first argument. Both take a
- * variable number of family-specific model-stepping ranges created by
- * AMD_MODEL_RANGE().
- *
- * Example:
- *
- * const int amd_erratum_319[] =
- * AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0x4, 0x2),
- * AMD_MODEL_RANGE(0x10, 0x8, 0x0, 0x8, 0x0),
- * AMD_MODEL_RANGE(0x10, 0x9, 0x0, 0x9, 0x0));
- */
-
-#define AMD_LEGACY_ERRATUM(...) { -1, __VA_ARGS__, 0 }
-#define AMD_OSVW_ERRATUM(osvw_id, ...) { osvw_id, __VA_ARGS__, 0 }
-#define AMD_MODEL_RANGE(f, m_start, s_start, m_end, s_end) \
- ((f << 24) | (m_start << 16) | (s_start << 12) | (m_end << 4) | (s_end))
-#define AMD_MODEL_RANGE_FAMILY(range) (((range) >> 24) & 0xff)
-#define AMD_MODEL_RANGE_START(range) (((range) >> 12) & 0xfff)
-#define AMD_MODEL_RANGE_END(range) ((range) & 0xfff)
-
-static const int amd_erratum_400[] =
- AMD_OSVW_ERRATUM(1, AMD_MODEL_RANGE(0xf, 0x41, 0x2, 0xff, 0xf),
- AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0xff, 0xf));
-
-static const int amd_erratum_383[] =
- AMD_OSVW_ERRATUM(3, AMD_MODEL_RANGE(0x10, 0, 0, 0xff, 0xf));
-
-/* #1054: Instructions Retired Performance Counter May Be Inaccurate */
-static const int amd_erratum_1054[] =
- AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x17, 0, 0, 0x2f, 0xf));
-
-static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum)
-{
- int osvw_id = *erratum++;
- u32 range;
- u32 ms;
-
- if (osvw_id >= 0 && osvw_id < 65536 &&
- cpu_has(cpu, X86_FEATURE_OSVW)) {
- u64 osvw_len;
-
- rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, osvw_len);
- if (osvw_id < osvw_len) {
- u64 osvw_bits;
-
- rdmsrl(MSR_AMD64_OSVW_STATUS + (osvw_id >> 6),
- osvw_bits);
- return osvw_bits & (1ULL << (osvw_id & 0x3f));
- }
- }
-
- /* OSVW unavailable or ID unknown, match family-model-stepping range */
- ms = (cpu->x86_model << 4) | cpu->x86_stepping;
- while ((range = *erratum++))
- if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range)) &&
- (ms >= AMD_MODEL_RANGE_START(range)) &&
- (ms <= AMD_MODEL_RANGE_END(range)))
- return true;
-
- return false;
-}
-
void set_dr_addr_mask(unsigned long mask, int dr)
{
if (!boot_cpu_has(X86_FEATURE_BPEXT))
--
2.25.1

172 changes: 172 additions & 0 deletions packages/kernel-5.10/5002-x86-cpu-amd-Add-a-Zenbleed-fix.patch
Original file line number Diff line number Diff line change
@@ -0,0 +1,172 @@
From 93df00f9d48d48466ddbe01a06eaaf3311ecfb53 Mon Sep 17 00:00:00 2001
From: "Borislav Petkov (AMD)" <[email protected]>
Date: Sat, 15 Jul 2023 13:41:28 +0200
Subject: [PATCH] x86/cpu/amd: Add a Zenbleed fix

Upstream commit: 522b1d69219d8f083173819fde04f994aa051a98

Add a fix for the Zen2 VZEROUPPER data corruption bug where under
certain circumstances executing VZEROUPPER can cause register
corruption or leak data.

The optimal fix is through microcode but in the case the proper
microcode revision has not been applied, enable a fallback fix using
a chicken bit.

Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/x86/include/asm/microcode.h | 1 +
arch/x86/include/asm/microcode_amd.h | 2 +
arch/x86/include/asm/msr-index.h | 1 +
arch/x86/kernel/cpu/amd.c | 60 ++++++++++++++++++++++++++++
arch/x86/kernel/cpu/common.c | 2 +
5 files changed, 66 insertions(+)

diff --git a/arch/x86/include/asm/microcode.h b/arch/x86/include/asm/microcode.h
index 509cc0262fdc..394605e59f2b 100644
--- a/arch/x86/include/asm/microcode.h
+++ b/arch/x86/include/asm/microcode.h
@@ -5,6 +5,7 @@
#include <asm/cpu.h>
#include <linux/earlycpio.h>
#include <linux/initrd.h>
+#include <asm/microcode_amd.h>

struct ucode_patch {
struct list_head plist;
diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h
index a645b25ee442..403a8e76b310 100644
--- a/arch/x86/include/asm/microcode_amd.h
+++ b/arch/x86/include/asm/microcode_amd.h
@@ -48,11 +48,13 @@ extern void __init load_ucode_amd_bsp(unsigned int family);
extern void load_ucode_amd_ap(unsigned int family);
extern int __init save_microcode_in_initrd_amd(unsigned int family);
void reload_ucode_amd(unsigned int cpu);
+extern void amd_check_microcode(void);
#else
static inline void __init load_ucode_amd_bsp(unsigned int family) {}
static inline void load_ucode_amd_ap(unsigned int family) {}
static inline int __init
save_microcode_in_initrd_amd(unsigned int family) { return -EINVAL; }
static inline void reload_ucode_amd(unsigned int cpu) {}
+static inline void amd_check_microcode(void) {}
#endif
#endif /* _ASM_X86_MICROCODE_AMD_H */
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index f71a177b6b18..3fab152809ab 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -497,6 +497,7 @@
#define MSR_AMD64_DE_CFG 0xc0011029
#define MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT 1
#define MSR_AMD64_DE_CFG_LFENCE_SERIALIZE BIT_ULL(MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT)
+#define MSR_AMD64_DE_CFG_ZEN2_FP_BACKUP_FIX_BIT 9

#define MSR_AMD64_BU_CFG2 0xc001102a
#define MSR_AMD64_IBSFETCHCTL 0xc0011030
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 6eea37f827b1..3d99a823ffac 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -71,6 +71,11 @@ static const int amd_erratum_383[] =
static const int amd_erratum_1054[] =
AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x17, 0, 0, 0x2f, 0xf));

+static const int amd_zenbleed[] =
+ AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x17, 0x30, 0x0, 0x4f, 0xf),
+ AMD_MODEL_RANGE(0x17, 0x60, 0x0, 0x7f, 0xf),
+ AMD_MODEL_RANGE(0x17, 0xa0, 0x0, 0xaf, 0xf));
+
static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum)
{
int osvw_id = *erratum++;
@@ -1030,6 +1035,47 @@ static void init_amd_zn(struct cpuinfo_x86 *c)
}
}

+static bool cpu_has_zenbleed_microcode(void)
+{
+ u32 good_rev = 0;
+
+ switch (boot_cpu_data.x86_model) {
+ case 0x30 ... 0x3f: good_rev = 0x0830107a; break;
+ case 0x60 ... 0x67: good_rev = 0x0860010b; break;
+ case 0x68 ... 0x6f: good_rev = 0x08608105; break;
+ case 0x70 ... 0x7f: good_rev = 0x08701032; break;
+ case 0xa0 ... 0xaf: good_rev = 0x08a00008; break;
+
+ default:
+ return false;
+ break;
+ }
+
+ if (boot_cpu_data.microcode < good_rev)
+ return false;
+
+ return true;
+}
+
+static void zenbleed_check(struct cpuinfo_x86 *c)
+{
+ if (!cpu_has_amd_erratum(c, amd_zenbleed))
+ return;
+
+ if (cpu_has(c, X86_FEATURE_HYPERVISOR))
+ return;
+
+ if (!cpu_has(c, X86_FEATURE_AVX))
+ return;
+
+ if (!cpu_has_zenbleed_microcode()) {
+ pr_notice_once("Zenbleed: please update your microcode for the most optimal fix\n");
+ msr_set_bit(MSR_AMD64_DE_CFG, MSR_AMD64_DE_CFG_ZEN2_FP_BACKUP_FIX_BIT);
+ } else {
+ msr_clear_bit(MSR_AMD64_DE_CFG, MSR_AMD64_DE_CFG_ZEN2_FP_BACKUP_FIX_BIT);
+ }
+}
+
static void init_amd(struct cpuinfo_x86 *c)
{
early_init_amd(c);
@@ -1120,6 +1166,8 @@ static void init_amd(struct cpuinfo_x86 *c)
msr_set_bit(MSR_K7_HWCR, MSR_K7_HWCR_IRPERF_EN_BIT);

check_null_seg_clears_base(c);
+
+ zenbleed_check(c);
}

#ifdef CONFIG_X86_32
@@ -1233,3 +1281,15 @@ void set_dr_addr_mask(unsigned long mask, int dr)
break;
}
}
+
+static void zenbleed_check_cpu(void *unused)
+{
+ struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());
+
+ zenbleed_check(c);
+}
+
+void amd_check_microcode(void)
+{
+ on_each_cpu(zenbleed_check_cpu, NULL, 1);
+}
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index e2dee6010846..f41781d06a5f 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2165,6 +2165,8 @@ void microcode_check(struct cpuinfo_x86 *prev_info)

perf_check_microcode();

+ amd_check_microcode();
+
store_cpu_caps(&curr_info);

if (!memcmp(&prev_info->x86_capability, &curr_info.x86_capability,
--
2.25.1

5 changes: 5 additions & 0 deletions packages/kernel-5.10/kernel-5.10.spec
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,11 @@ Patch1003: 1003-af_unix-increase-default-max_dgram_qlen-to-512.patch
Patch2000: 2000-kbuild-move-module-strip-compression-code-into-scrip.patch
Patch2001: 2001-kbuild-add-support-for-zstd-compressed-modules.patch

# Cherry-picked fix for CVE-2023-20593 ("Zenbleed"). Can be dropped when moving
# upstream to 5.10.187 or later.
Patch5001: 5001-x86-cpu-amd-Move-the-errata-checking-functionality-u.patch
Patch5002: 5002-x86-cpu-amd-Add-a-Zenbleed-fix.patch

BuildRequires: bc
BuildRequires: elfutils-devel
BuildRequires: hostname
Expand Down
Loading

0 comments on commit edf01e2

Please sign in to comment.