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Linux 5.10.123

DISCUSSION Greg Kroah-Hartman 1 participant 2 messages Jun 16, 2022 Stable branch

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Greg Kroah-Hartman

author maintainer
#0 lore raw

I'm announcing the release of the 5.10.123 kernel.

All users of the 5.10 kernel series must upgrade.

The updated 5.10.y git tree can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-5.10.y
and can be browsed at the normal kernel.org git web browser:
https://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary

thanks,

greg k-h

------------

 Documentation/ABI/testing/sysfs-devices-system-cpu              |    1 
 Documentation/admin-guide/hw-vuln/index.rst                     |    1 
 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst |  246 ++++++++++
 Documentation/admin-guide/kernel-parameters.txt                 |   36 +
 Makefile                                                        |    2 
 arch/x86/include/asm/cpufeatures.h                              |    1 
 arch/x86/include/asm/msr-index.h                                |   25 +
 arch/x86/include/asm/nospec-branch.h                            |    2 
 arch/x86/kernel/cpu/bugs.c                                      |  235 ++++++++-
 arch/x86/kernel/cpu/common.c                                    |   52 +-
 arch/x86/kvm/vmx/vmx.c                                          |   72 ++
 arch/x86/kvm/vmx/vmx.h                                          |    2 
 arch/x86/kvm/x86.c                                              |    3 
 drivers/base/cpu.c                                              |    8 
 include/linux/cpu.h                                             |    3 
 tools/arch/x86/include/asm/cpufeatures.h                        |    1 
 tools/arch/x86/include/asm/msr-index.h                          |   25 +
 17 files changed, 675 insertions(+), 40 deletions(-)

Greg Kroah-Hartman (1):

      Linux 5.10.123

Josh Poimboeuf (1):
x86/speculation/mmio: Print SMT warning

Pawan Gupta (10):
Documentation: Add documentation for Processor MMIO Stale Data x86/speculation/mmio: Enumerate Processor MMIO Stale Data bug x86/speculation: Add a common function for MD_CLEAR mitigation update x86/speculation/mmio: Add mitigation for Processor MMIO Stale Data x86/bugs: Group MDS, TAA & Processor MMIO Stale Data mitigations x86/speculation/mmio: Enable CPU Fill buffer clearing on idle x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data x86/speculation/srbds: Update SRBDS mitigation selection x86/speculation/mmio: Reuse SRBDS mitigation for SBDS
KVM: x86/speculation: Disable Fill buffer clear within guests

author maintainer
#1 lore raw
Documentation/ABI/testing/sysfs-devices-system-cpu +1 -0
index 1a04ca8162ad..44c6e5730398 100644
@@ -510,6 +510,7 @@ What:		/sys/devices/system/cpu/vulnerabilities
 		/sys/devices/system/cpu/vulnerabilities/srbds
 		/sys/devices/system/cpu/vulnerabilities/tsx_async_abort
 		/sys/devices/system/cpu/vulnerabilities/itlb_multihit
+		/sys/devices/system/cpu/vulnerabilities/mmio_stale_data
 Date:		January 2018
 Contact:	Linux kernel mailing list <[email protected]>
 Description:	Information about CPU vulnerabilities
Documentation/admin-guide/hw-vuln/index.rst +1 -0
index ca4dbdd9016d..2adec1e6520a 100644
@@ -15,3 +15,4 @@ are configurable at compile, boot or run time.
    tsx_async_abort
    multihit.rst
    special-register-buffer-data-sampling.rst
+   processor_mmio_stale_data.rst
Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst new file +246 -0

246 lines not on this page · raw message

Documentation/admin-guide/kernel-parameters.txt +36 -0
index 5e34deec819f..ea8b704be705 100644
@@ -2872,6 +2872,7 @@
 					       kvm.nx_huge_pages=off [X86]
 					       no_entry_flush [PPC]
 					       no_uaccess_flush [PPC]
+					       mmio_stale_data=off [X86]
 
 				Exceptions:
 					       This does not have any effect on
@@ -2893,6 +2894,7 @@
 				Equivalent to: l1tf=flush,nosmt [X86]
 					       mds=full,nosmt [X86]
 					       tsx_async_abort=full,nosmt [X86]
+					       mmio_stale_data=full,nosmt [X86]
 
 	mminit_loglevel=
 			[KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
@@ -2902,6 +2904,40 @@
 			log everything. Information is printed at KERN_DEBUG
 			so loglevel=8 may also need to be specified.
 
+	mmio_stale_data=
+			[X86,INTEL] Control mitigation for the Processor
+			MMIO Stale Data vulnerabilities.
+
+			Processor MMIO Stale Data is a class of
+			vulnerabilities that may expose data after an MMIO
+			operation. Exposed data could originate or end in
+			the same CPU buffers as affected by MDS and TAA.
+			Therefore, similar to MDS and TAA, the mitigation
+			is to clear the affected CPU buffers.
+
+			This parameter controls the mitigation. The
+			options are:
+
+			full       - Enable mitigation on vulnerable CPUs
+
+			full,nosmt - Enable mitigation and disable SMT on
+				     vulnerable CPUs.
+
+			off        - Unconditionally disable mitigation
+
+			On MDS or TAA affected machines,
+			mmio_stale_data=off can be prevented by an active
+			MDS or TAA mitigation as these vulnerabilities are
+			mitigated with the same mechanism so in order to
+			disable this mitigation, you need to specify
+			mds=off and tsx_async_abort=off too.
+
+			Not specifying this option is equivalent to
+			mmio_stale_data=full.
+
+			For details see:
+			Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
+
 	module.sig_enforce
 			[KNL] When CONFIG_MODULE_SIG is set, this means that
 			modules without (valid) signatures will fail to load.
Makefile +1 -1
index 3ed1da61a3c7..862946040186 100644
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 5
 PATCHLEVEL = 10
-SUBLEVEL = 122
+SUBLEVEL = 123
 EXTRAVERSION =
 NAME = Dare mighty things
 
arch/x86/include/asm/cpufeatures.h +1 -0
index 3b407f46f1a0..f6a6ac0b3bcd 100644
@@ -417,5 +417,6 @@
 #define X86_BUG_TAA			X86_BUG(22) /* CPU is affected by TSX Async Abort(TAA) */
 #define X86_BUG_ITLB_MULTIHIT		X86_BUG(23) /* CPU may incur MCE during certain page attribute changes */
 #define X86_BUG_SRBDS			X86_BUG(24) /* CPU may leak RNG bits if not mitigated */
+#define X86_BUG_MMIO_STALE_DATA		X86_BUG(25) /* CPU is affected by Processor MMIO Stale Data vulnerabilities */
 
 #endif /* _ASM_X86_CPUFEATURES_H */
arch/x86/include/asm/msr-index.h +25 -0
index 972a34d93505..96973d197972 100644
@@ -114,6 +114,30 @@
 						 * Not susceptible to
 						 * TSX Async Abort (TAA) vulnerabilities.
 						 */
+#define ARCH_CAP_SBDR_SSDP_NO		BIT(13)	/*
+						 * Not susceptible to SBDR and SSDP
+						 * variants of Processor MMIO stale data
+						 * vulnerabilities.
+						 */
+#define ARCH_CAP_FBSDP_NO		BIT(14)	/*
+						 * Not susceptible to FBSDP variant of
+						 * Processor MMIO stale data
+						 * vulnerabilities.
+						 */
+#define ARCH_CAP_PSDP_NO		BIT(15)	/*
+						 * Not susceptible to PSDP variant of
+						 * Processor MMIO stale data
+						 * vulnerabilities.
+						 */
+#define ARCH_CAP_FB_CLEAR		BIT(17)	/*
+						 * VERW clears CPU fill buffer
+						 * even on MDS_NO CPUs.
+						 */
+#define ARCH_CAP_FB_CLEAR_CTRL		BIT(18)	/*
+						 * MSR_IA32_MCU_OPT_CTRL[FB_CLEAR_DIS]
+						 * bit available to control VERW
+						 * behavior.
+						 */
 
 #define MSR_IA32_FLUSH_CMD		0x0000010b
 #define L1D_FLUSH			BIT(0)	/*
@@ -131,6 +155,7 @@
 /* SRBDS support */
 #define MSR_IA32_MCU_OPT_CTRL		0x00000123
 #define RNGDS_MITG_DIS			BIT(0)
+#define FB_CLEAR_DIS			BIT(3)	/* CPU Fill buffer clear disable */
 
 #define MSR_IA32_SYSENTER_CS		0x00000174
 #define MSR_IA32_SYSENTER_ESP		0x00000175
arch/x86/include/asm/nospec-branch.h +2 -0
index 4d0f5386e637..e247151c3dcf 100644
@@ -255,6 +255,8 @@ DECLARE_STATIC_KEY_FALSE(switch_mm_always_ibpb);
 DECLARE_STATIC_KEY_FALSE(mds_user_clear);
 DECLARE_STATIC_KEY_FALSE(mds_idle_clear);
 
+DECLARE_STATIC_KEY_FALSE(mmio_stale_data_clear);
+
 #include <asm/segment.h>
 
 /**
arch/x86/kernel/cpu/bugs.c +199 -36

334 lines not on this page · raw message

arch/x86/kernel/cpu/common.c +49 -3

85 lines not on this page · raw message

arch/x86/kvm/vmx/vmx.c +72 -0

114 lines not on this page · raw message

arch/x86/kvm/vmx/vmx.h +2 -0
index 5ff24537393e..31317c8915e4 100644
@@ -300,6 +300,8 @@ struct vcpu_vmx {
 	u64 msr_ia32_feature_control;
 	u64 msr_ia32_feature_control_valid_bits;
 	u64 ept_pointer;
+	u64 msr_ia32_mcu_opt_ctrl;
+	bool disable_fb_clear;
 
 	struct pt_desc pt_desc;
 
arch/x86/kvm/x86.c +3 -0
index d9cec5daa1ff..da547752580a 100644
@@ -1415,6 +1415,9 @@ static u64 kvm_get_arch_capabilities(void)
 		 */
 	}
 
+	/* Guests don't need to know "Fill buffer clear control" exists */
+	data &= ~ARCH_CAP_FB_CLEAR_CTRL;
+
 	return data;
 }
 
drivers/base/cpu.c +8 -0
index 8f1d6569564c..8ecb9f90f467 100644
@@ -566,6 +566,12 @@ ssize_t __weak cpu_show_srbds(struct device *dev,
 	return sysfs_emit(buf, "Not affected\n");
 }
 
+ssize_t __weak cpu_show_mmio_stale_data(struct device *dev,
+					struct device_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "Not affected\n");
+}
+
 static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
 static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
 static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
@@ -575,6 +581,7 @@ static DEVICE_ATTR(mds, 0444, cpu_show_mds, NULL);
 static DEVICE_ATTR(tsx_async_abort, 0444, cpu_show_tsx_async_abort, NULL);
 static DEVICE_ATTR(itlb_multihit, 0444, cpu_show_itlb_multihit, NULL);
 static DEVICE_ATTR(srbds, 0444, cpu_show_srbds, NULL);
+static DEVICE_ATTR(mmio_stale_data, 0444, cpu_show_mmio_stale_data, NULL);
 
 static struct attribute *cpu_root_vulnerabilities_attrs[] = {
 	&dev_attr_meltdown.attr,
@@ -586,6 +593,7 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = {
 	&dev_attr_tsx_async_abort.attr,
 	&dev_attr_itlb_multihit.attr,
 	&dev_attr_srbds.attr,
+	&dev_attr_mmio_stale_data.attr,
 	NULL
 };
 
include/linux/cpu.h +3 -0
index d6428aaf67e7..d63b8f70d123 100644
@@ -65,6 +65,9 @@ extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
 extern ssize_t cpu_show_itlb_multihit(struct device *dev,
 				      struct device_attribute *attr, char *buf);
 extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf);
+extern ssize_t cpu_show_mmio_stale_data(struct device *dev,
+					struct device_attribute *attr,
+					char *buf);
 
 extern __printf(4, 5)
 struct device *cpu_device_create(struct device *parent, void *drvdata,
tools/arch/x86/include/asm/cpufeatures.h +1 -0
index b58730cc12e8..a7b5c5efcf3b 100644
@@ -417,5 +417,6 @@
 #define X86_BUG_TAA			X86_BUG(22) /* CPU is affected by TSX Async Abort(TAA) */
 #define X86_BUG_ITLB_MULTIHIT		X86_BUG(23) /* CPU may incur MCE during certain page attribute changes */
 #define X86_BUG_SRBDS			X86_BUG(24) /* CPU may leak RNG bits if not mitigated */
+#define X86_BUG_MMIO_STALE_DATA		X86_BUG(25) /* CPU is affected by Processor MMIO Stale Data vulnerabilities */
 
 #endif /* _ASM_X86_CPUFEATURES_H */
tools/arch/x86/include/asm/msr-index.h +25 -0
index 972a34d93505..96973d197972 100644
@@ -114,6 +114,30 @@
 						 * Not susceptible to
 						 * TSX Async Abort (TAA) vulnerabilities.
 						 */
+#define ARCH_CAP_SBDR_SSDP_NO		BIT(13)	/*
+						 * Not susceptible to SBDR and SSDP
+						 * variants of Processor MMIO stale data
+						 * vulnerabilities.
+						 */
+#define ARCH_CAP_FBSDP_NO		BIT(14)	/*
+						 * Not susceptible to FBSDP variant of
+						 * Processor MMIO stale data
+						 * vulnerabilities.
+						 */
+#define ARCH_CAP_PSDP_NO		BIT(15)	/*
+						 * Not susceptible to PSDP variant of
+						 * Processor MMIO stale data
+						 * vulnerabilities.
+						 */
+#define ARCH_CAP_FB_CLEAR		BIT(17)	/*
+						 * VERW clears CPU fill buffer
+						 * even on MDS_NO CPUs.
+						 */
+#define ARCH_CAP_FB_CLEAR_CTRL		BIT(18)	/*
+						 * MSR_IA32_MCU_OPT_CTRL[FB_CLEAR_DIS]
+						 * bit available to control VERW
+						 * behavior.
+						 */
 
 #define MSR_IA32_FLUSH_CMD		0x0000010b
 #define L1D_FLUSH			BIT(0)	/*
@@ -131,6 +155,7 @@
 /* SRBDS support */
 #define MSR_IA32_MCU_OPT_CTRL		0x00000123
 #define RNGDS_MITG_DIS			BIT(0)
+#define FB_CLEAR_DIS			BIT(3)	/* CPU Fill buffer clear disable */
 
 #define MSR_IA32_SYSENTER_CS		0x00000174
 #define MSR_IA32_SYSENTER_ESP		0x00000175