From: "Chang S. Bae" <chang.seok.bae@intel.com>
To: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org
Cc: ebiggers@kernel.org, luto@kernel.org,
dave.hansen@linux.intel.com, tglx@linutronix.de, bp@alien8.de,
mingo@kernel.org, x86@kernel.org, herbert@gondor.apana.org.au,
ardb@kernel.org, elliott@hpe.com, dan.j.williams@intel.com,
bernie.keany@intel.com, charishma1.gairuboyina@intel.com,
chang.seok.bae@intel.com, Dave Hansen <dave.hansen@intel.com>,
Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Subject: [PATCH v9a 11/14] x86/cpu/keylocker: Check Register File Data Sampling mitigation
Date: Sun, 7 Apr 2024 16:04:43 -0700 [thread overview]
Message-ID: <20240407230443.912306-1-chang.seok.bae@intel.com> (raw)
In-Reply-To: <20240329062057.kt5dkoffbkkxdt7x@desk>
The Register File Data Sampling vulnerability may allow malicious
userspace programs to infer stale kernel register data, potentially
exposing sensitive key values, including AES keys.
To address this vulnerability, a microcode update needs to be applied to
the CPU, which modifies the VERW instruction to flush the affected CPU
buffers.
Reference the 'rfds_mitigation' variable to check the mitigation status.
Do not enable Key Locker on CPUs affected by the vulnerability but
lacking mitigation.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
---
Changes from v9:
* Remove the helper function and simplify the code by directly reading
the status variable. (Pawan Gupta)
Note that this code change aligns with mitigation guidance, which
recommends:
"Software loading Key Locker keys using LOADIWKEY should execute a VERW
to clear registers before transitioning to untrusted code to prevent
later software from inferring the loaded key."
For more information, refer to Intel's guidance on Register File Data
Sampling:
https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/advisory-guidance/register-file-data-sampling.html
---
arch/x86/include/asm/processor.h | 8 ++++++++
arch/x86/kernel/cpu/bugs.c | 8 +-------
arch/x86/kernel/keylocker.c | 3 +++
3 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 74eaa3a2b85b..b823163f4786 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -728,6 +728,14 @@ enum mitigation_info {
extern bool gds_ucode_mitigated(enum mitigation_info mitg);
+enum rfds_mitigations {
+ RFDS_MITIGATION_OFF,
+ RFDS_MITIGATION_VERW,
+ RFDS_MITIGATION_UCODE_NEEDED,
+};
+
+extern enum rfds_mitigations rfds_mitigation;
+
/*
* Make previous memory operations globally visible before
* a WRMSR.
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 80f6e70619cb..a2ba1a0ef872 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -483,14 +483,8 @@ early_param("mmio_stale_data", mmio_stale_data_parse_cmdline);
#undef pr_fmt
#define pr_fmt(fmt) "Register File Data Sampling: " fmt
-enum rfds_mitigations {
- RFDS_MITIGATION_OFF,
- RFDS_MITIGATION_VERW,
- RFDS_MITIGATION_UCODE_NEEDED,
-};
-
/* Default mitigation for Register File Data Sampling */
-static enum rfds_mitigations rfds_mitigation __ro_after_init =
+enum rfds_mitigations rfds_mitigation __ro_after_init =
IS_ENABLED(CONFIG_MITIGATION_RFDS) ? RFDS_MITIGATION_VERW : RFDS_MITIGATION_OFF;
static const char * const rfds_strings[] = {
diff --git a/arch/x86/kernel/keylocker.c b/arch/x86/kernel/keylocker.c
index 23cf4a235f11..09876693414c 100644
--- a/arch/x86/kernel/keylocker.c
+++ b/arch/x86/kernel/keylocker.c
@@ -119,6 +119,9 @@ static bool __init secure_keylocker(void)
if (boot_cpu_has_bug(X86_BUG_GDS) && !gds_ucode_mitigated(MITG_LOCKED))
return false;
+ if (boot_cpu_has_bug(X86_BUG_RFDS) && rfds_mitigation != RFDS_MITIGATION_VERW)
+ return false;
+
return true;
}
--
2.40.1
next prev parent reply other threads:[~2024-04-07 23:20 UTC|newest]
Thread overview: 147+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-12 21:12 [PATCH v5 00/12] x86: Support Key Locker Chang S. Bae
2022-01-12 21:12 ` [PATCH v5 01/12] Documentation/x86: Document " Chang S. Bae
2023-06-05 10:52 ` Bagas Sanjaya
2022-01-12 21:12 ` [PATCH v5 02/12] x86/cpufeature: Enumerate Key Locker feature Chang S. Bae
2022-01-12 21:12 ` [PATCH v5 03/12] x86/insn: Add Key Locker instructions to the opcode map Chang S. Bae
2022-01-12 21:12 ` [PATCH v5 04/12] x86/asm: Add a wrapper function for the LOADIWKEY instruction Chang S. Bae
2022-01-12 21:12 ` [PATCH v5 05/12] x86/msr-index: Add MSRs for Key Locker internal wrapping key Chang S. Bae
2022-01-12 21:12 ` [PATCH v5 06/12] x86/keylocker: Define Key Locker CPUID leaf Chang S. Bae
2022-01-12 21:12 ` [PATCH v5 07/12] x86/cpu/keylocker: Load an internal wrapping key at boot-time Chang S. Bae
2022-08-23 15:49 ` Evan Green
2022-08-24 22:20 ` Chang S. Bae
2022-08-24 22:52 ` Evan Green
2022-08-25 1:06 ` Chang S. Bae
2022-08-25 15:31 ` Evan Green
2022-08-31 23:08 ` Chang S. Bae
2022-09-06 16:22 ` Evan Green
2022-09-06 16:46 ` Chang S. Bae
2022-01-12 21:12 ` [PATCH v5 08/12] x86/PM/keylocker: Restore internal wrapping key on resume from ACPI S3/4 Chang S. Bae
2022-01-29 17:31 ` [PATCH v5-fix " Chang S. Bae
2022-01-12 21:12 ` [PATCH v5 09/12] x86/cpu: Add a configuration and command line option for Key Locker Chang S. Bae
2022-01-12 21:12 ` [PATCH v5 10/12] crypto: x86/aes - Prepare for a new AES implementation Chang S. Bae
2022-01-12 21:12 ` [PATCH v5 11/12] crypto: x86/aes-kl - Support AES algorithm using Key Locker instructions Chang S. Bae
2022-01-12 21:12 ` [PATCH v5 12/12] crypto: x86/aes-kl - Support XTS mode Chang S. Bae
2022-01-13 22:16 ` [PATCH v5 00/12] x86: Support Key Locker Dave Hansen
2022-01-13 22:34 ` Bae, Chang Seok
2023-04-10 22:59 ` [PATCH v6 " Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 01/12] Documentation/x86: Document " Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 02/12] x86/cpufeature: Enumerate Key Locker feature Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 03/12] x86/insn: Add Key Locker instructions to the opcode map Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 04/12] x86/asm: Add a wrapper function for the LOADIWKEY instruction Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 05/12] x86/msr-index: Add MSRs for Key Locker internal wrapping key Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 06/12] x86/keylocker: Define Key Locker CPUID leaf Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 07/12] x86/cpu/keylocker: Load an internal wrapping key at boot-time Chang S. Bae
2023-05-05 23:05 ` Eric Biggers
2023-05-08 18:18 ` Chang S. Bae
2023-05-08 21:56 ` Dave Hansen
2023-05-09 0:31 ` Chang S. Bae
2023-05-09 0:51 ` Dave Hansen
2023-05-08 19:18 ` Elliott, Robert (Servers)
2023-05-08 20:15 ` Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 08/12] x86/PM/keylocker: Restore internal wrapping key on resume from ACPI S3/4 Chang S. Bae
2023-05-05 23:09 ` Eric Biggers
2023-05-08 18:18 ` Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 09/12] x86/cpu: Add a configuration and command line option for Key Locker Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 10/12] crypto: x86/aes - Prepare for a new AES implementation Chang S. Bae
2023-05-05 23:27 ` Eric Biggers
2023-05-09 0:55 ` Chang S. Bae
2023-05-11 19:05 ` Chang S. Bae
2023-05-11 21:39 ` Eric Biggers
2023-05-11 23:19 ` Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 11/12] crypto: x86/aes-kl - Support AES algorithm using Key Locker instructions Chang S. Bae
2023-05-06 0:01 ` Eric Biggers
2023-05-08 18:18 ` Chang S. Bae
2023-05-24 17:18 ` Chang S. Bae
2023-05-12 17:52 ` Milan Broz
2023-05-08 19:21 ` Elliott, Robert (Servers)
2023-05-08 19:24 ` Elliott, Robert (Servers)
2023-05-08 20:00 ` Chang S. Bae
2023-04-10 22:59 ` [PATCH v6 12/12] crypto: x86/aes-kl - Support XTS mode Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 00/12] x86: Support Key Locker Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 01/12] Documentation/x86: Document " Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 02/12] x86/cpufeature: Enumerate Key Locker feature Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 03/12] x86/insn: Add Key Locker instructions to the opcode map Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 04/12] x86/asm: Add a wrapper function for the LOADIWKEY instruction Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 05/12] x86/msr-index: Add MSRs for Key Locker wrapping key Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 06/12] x86/keylocker: Define Key Locker CPUID leaf Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 07/12] x86/cpu/keylocker: Load a wrapping key at boot-time Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 08/12] x86/PM/keylocker: Restore the wrapping key on the resume from ACPI S3/4 Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 09/12] x86/cpu: Add a configuration and command line option for Key Locker Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 10/12] crypto: x86/aesni - Use the proper data type in struct aesni_xts_ctx Chang S. Bae
2023-05-26 6:54 ` Eric Biggers
2023-05-30 20:50 ` Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 11/12] crypto: x86/aes - Prepare for a new AES implementation Chang S. Bae
2023-05-24 16:57 ` [PATCH v7 12/12] crypto: x86/aes-kl - Implement the AES-XTS algorithm Chang S. Bae
2023-05-26 7:23 ` Eric Biggers
2023-05-30 20:49 ` Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 00/12] x86: Support Key Locker Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 01/12] Documentation/x86: Document " Chang S. Bae
2023-06-05 10:54 ` Bagas Sanjaya
2023-06-06 2:17 ` Randy Dunlap
2023-06-06 4:18 ` Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 02/12] x86/cpufeature: Enumerate Key Locker feature Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 03/12] x86/insn: Add Key Locker instructions to the opcode map Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 04/12] x86/asm: Add a wrapper function for the LOADIWKEY instruction Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 05/12] x86/msr-index: Add MSRs for Key Locker wrapping key Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 06/12] x86/keylocker: Define Key Locker CPUID leaf Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 07/12] x86/cpu/keylocker: Load a wrapping key at boot-time Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 08/12] x86/PM/keylocker: Restore the wrapping key on the resume from ACPI S3/4 Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 09/12] x86/cpu: Add a configuration and command line option for Key Locker Chang S. Bae
2023-06-03 16:37 ` Borislav Petkov
2023-06-04 22:13 ` Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 10/12] crypto: x86/aesni - Use the proper data type in struct aesni_xts_ctx Chang S. Bae
2023-06-04 15:34 ` Eric Biggers
2023-06-04 22:02 ` Chang S. Bae
2023-06-05 2:46 ` Eric Biggers
2023-06-05 4:41 ` Chang S. Bae
2023-06-21 12:06 ` [PATCH] crypto: x86/aesni: Align the address before aes_set_key_common() Chang S. Bae
2023-07-14 8:51 ` Herbert Xu
2023-06-03 15:22 ` [PATCH v8 11/12] crypto: x86/aes - Prepare for a new AES-XTS implementation Chang S. Bae
2023-06-03 15:22 ` [PATCH v8 12/12] crypto: x86/aes-kl - Implement the AES-XTS algorithm Chang S. Bae
2023-06-07 5:35 ` Eric Biggers
2023-06-07 22:06 ` Chang S. Bae
2024-03-11 21:32 ` [PATCH] crypto: x86/aesni - Update aesni_set_key() to return void Chang S. Bae
2024-03-12 2:15 ` Eric Biggers
2024-03-12 7:46 ` Ard Biesheuvel
2024-03-12 15:03 ` Chang S. Bae
2024-03-12 15:18 ` Ard Biesheuvel
2024-03-12 15:37 ` Chang S. Bae
2024-03-22 23:04 ` [PATCH v2 0/2] crypto: x86/aesni - Simplify AES key expansion code Chang S. Bae
2024-03-22 23:04 ` [PATCH v2 1/2] crypto: x86/aesni - Rearrange AES key size check Chang S. Bae
2024-03-22 23:04 ` [PATCH v2 2/2] crypto: x86/aesni - Update aesni_set_key() to return void Chang S. Bae
2024-03-28 10:57 ` [PATCH v2 0/2] crypto: x86/aesni - Simplify AES key expansion code Herbert Xu
2024-03-29 1:53 ` [PATCH v9 00/14] x86: Support Key Locker Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 01/14] Documentation/x86: Document " Chang S. Bae
2024-03-31 15:48 ` Randy Dunlap
2024-03-29 1:53 ` [PATCH v9 02/14] x86/cpufeature: Enumerate Key Locker feature Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 03/14] x86/insn: Add Key Locker instructions to the opcode map Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 04/14] x86/asm: Add a wrapper function for the LOADIWKEY instruction Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 05/14] x86/msr-index: Add MSRs for Key Locker wrapping key Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 06/14] x86/keylocker: Define Key Locker CPUID leaf Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 07/14] x86/cpu/keylocker: Load a wrapping key at boot time Chang S. Bae
2024-04-07 23:04 ` [PATCH v9a " Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 08/14] x86/PM/keylocker: Restore the wrapping key on the resume from ACPI S3/4 Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 09/14] x86/hotplug/keylocker: Ensure wrapping key backup capability Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 10/14] x86/cpu/keylocker: Check Gather Data Sampling mitigation Chang S. Bae
2024-03-29 6:57 ` Pawan Gupta
2024-04-07 23:04 ` [PATCH v9a " Chang S. Bae
2024-04-19 0:01 ` Pawan Gupta
2024-04-22 7:49 ` Chang S. Bae
2024-04-19 17:47 ` [PATCH 15/14] x86/gds: Lock GDS mitigation when keylocker feature is present Pawan Gupta
2024-04-19 18:03 ` Daniel Sneddon
2024-04-19 20:19 ` Pawan Gupta
2024-04-19 20:33 ` Daniel Sneddon
2024-04-22 7:35 ` Chang S. Bae
2024-04-22 21:32 ` Pawan Gupta
2024-04-22 22:13 ` Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 11/14] x86/cpu/keylocker: Check Register File Data Sampling mitigation Chang S. Bae
2024-03-29 6:20 ` Pawan Gupta
2024-04-07 23:04 ` Chang S. Bae [this message]
2024-03-29 1:53 ` [PATCH v9 12/14] x86/Kconfig: Add a configuration for Key Locker Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 13/14] crypto: x86/aes - Prepare for new AES-XTS implementation Chang S. Bae
2024-03-29 1:53 ` [PATCH v9 14/14] crypto: x86/aes-kl - Implement the AES-XTS algorithm Chang S. Bae
2024-04-07 23:24 ` [PATCH v9 00/14] x86: Support Key Locker Chang S. Bae
2024-04-08 1:48 ` Eric Biggers
2024-04-15 22:16 ` Chang S. Bae
2024-04-15 22:54 ` Eric Biggers
2024-04-15 22:58 ` Chang S. Bae
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