FAILED: patch "[PATCH] x86/speculation: Make all RETbleed mitigations 64-bit only" failed to apply to 5.10-stable tree
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[email protected]
maintainerThe patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b648ab487f31bc4c38941bc770ea97fe394304bb Mon Sep 17 00:00:00 2001
From: Ben Hutchings <[email protected]>
Date: Sat, 23 Jul 2022 17:22:47 +0200
Subject: [PATCH] x86/speculation: Make all RETbleed mitigations 64-bit only
The mitigations for RETBleed are currently ineffective on x86_32 since entry_32.S does not use the required macros. However, for an x86_32 target, the kconfig symbols for them are still enabled by default and /sys/devices/system/cpu/vulnerabilities/retbleed will wrongly report that mitigations are in place.
Make all of these symbols depend on X86_64, and only enable RETHUNK by default on X86_64.
arch/x86/Kconfig +4 -4
@@ -2473,7 +2473,7 @@ config RETHUNK bool "Enable return-thunks" depends on RETPOLINE && CC_HAS_RETURN_THUNK select OBJTOOL if HAVE_OBJTOOL - default y + default y if X86_64 help Compile the kernel with the return-thunks compiler option to guard against kernel-to-user data leaks by avoiding return speculation.
@@ -2482,21 +2482,21 @@ config RETHUNK config CPU_UNRET_ENTRY bool "Enable UNRET on kernel entry" - depends on CPU_SUP_AMD && RETHUNK + depends on CPU_SUP_AMD && RETHUNK && X86_64 default y help Compile the kernel with support for the retbleed=unret mitigation. config CPU_IBPB_ENTRY bool "Enable IBPB on kernel entry" - depends on CPU_SUP_AMD + depends on CPU_SUP_AMD && X86_64 default y help Compile the kernel with support for the retbleed=ibpb mitigation. config CPU_IBRS_ENTRY bool "Enable IBRS on kernel entry" - depends on CPU_SUP_INTEL + depends on CPU_SUP_INTEL && X86_64 default y help Compile the kernel with support for the spectre_v2=ibrs mitigation.
I'm attaching a backport that should work for all of 5.10, 5.15, and 5.18.
Ben.
Signature · 2 lines
Ben Hutchings Larkinson's Law: All laws are basically false.
From 999bc23969f190ec9aa54a0ca20a8c94e2d67ba1 Mon Sep 17 00:00:00 2001
From: Ben Hutchings <[email protected]>
Date: Sat, 23 Jul 2022 17:22:47 +0200
Subject: [PATCH] x86/speculation: Make all RETbleed mitigations 64-bit only
commit b648ab487f31bc4c38941bc770ea97fe394304bb upstream.
The mitigations for RETBleed are currently ineffective on x86_32 since entry_32.S does not use the required macros. However, for an x86_32 target, the kconfig symbols for them are still enabled by default and /sys/devices/system/cpu/vulnerabilities/retbleed will wrongly report that mitigations are in place.
Make all of these symbols depend on X86_64, and only enable RETHUNK by default on X86_64.
--- arch/x86/Kconfig | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
arch/x86/Kconfig +4 -4
@@ -2469,7 +2469,7 @@ config RETPOLINE config RETHUNK bool "Enable return-thunks" depends on RETPOLINE && CC_HAS_RETURN_THUNK - default y + default y if X86_64 help Compile the kernel with the return-thunks compiler option to guard against kernel-to-user data leaks by avoiding return speculation.
@@ -2478,21 +2478,21 @@ config RETHUNK config CPU_UNRET_ENTRY bool "Enable UNRET on kernel entry" - depends on CPU_SUP_AMD && RETHUNK + depends on CPU_SUP_AMD && RETHUNK && X86_64 default y help Compile the kernel with support for the retbleed=unret mitigation. config CPU_IBPB_ENTRY bool "Enable IBPB on kernel entry" - depends on CPU_SUP_AMD + depends on CPU_SUP_AMD && X86_64 default y help Compile the kernel with support for the retbleed=ibpb mitigation. config CPU_IBRS_ENTRY bool "Enable IBRS on kernel entry" - depends on CPU_SUP_INTEL + depends on CPU_SUP_INTEL && X86_64 default y help Compile the kernel with support for the spectre_v2=ibrs mitigation.
Greg KH
maintainerQuoted 3 lines · Ben Hutchings
I'm attaching a backport that should work for all of 5.10, 5.15, and 5.18.
Thanks, now queued up.
greg k-h