This is a note to let you know that I've just added the patch titled
x86/entry_32: Add VERW just before userspace transition
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-entry_32-add-verw-just-before-userspace-transition.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable+bounces-25866-greg=kroah.com@xxxxxxxxxxxxxxx Mon Mar 4 10:26:09 2024
From: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx>
Date: Mon, 4 Mar 2024 01:24:05 -0800
Subject: x86/entry_32: Add VERW just before userspace transition
To: stable@xxxxxxxxxxxxxxx
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Message-ID: <20240304-delay-verw-backport-6-1-y-v2-3-bf4bce517d60@xxxxxxxxxxxxxxx>
Content-Disposition: inline
From: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx>
commit a0e2dab44d22b913b4c228c8b52b2a104434b0b3 upstream.
As done for entry_64, add support for executing VERW late in exit to
user path for 32-bit mode.
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx>
Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20240213-delay-verw-v8-3-a6216d83edb7%40linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/entry/entry_32.S | 3 +++
1 file changed, 3 insertions(+)
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -912,6 +912,7 @@ SYM_FUNC_START(entry_SYSENTER_32)
BUG_IF_WRONG_CR3 no_user_check=1
popfl
popl %eax
+ CLEAR_CPU_BUFFERS
/*
* Return back to the vDSO, which will pop ecx and edx.
@@ -981,6 +982,7 @@ restore_all_switch_stack:
/* Restore user state */
RESTORE_REGS pop=4 # skip orig_eax/error_code
+ CLEAR_CPU_BUFFERS
.Lirq_return:
/*
* ARCH_HAS_MEMBARRIER_SYNC_CORE rely on IRET core serialization
@@ -1173,6 +1175,7 @@ SYM_CODE_START(asm_exc_nmi)
/* Not on SYSENTER stack. */
call exc_nmi
+ CLEAR_CPU_BUFFERS
jmp .Lnmi_return
.Lnmi_from_sysenter_stack:
Patches currently in stable-queue which might be from kroah.com@xxxxxxxxxxxxxxx are
queue-6.1/x86-bugs-use-alternative-instead-of-mds_user_clear-static-key.patch
queue-6.1/x86-decompressor-avoid-magic-offsets-for-efi-handover-entrypoint.patch
queue-6.1/x86-efistub-avoid-placing-the-kernel-below-load_physical_addr.patch
queue-6.1/x86-efistub-avoid-legacy-decompressor-when-doing-efi-boot.patch
queue-6.1/kvm-vmx-move-verw-closer-to-vmentry-for-mds-mitigation.patch
queue-6.1/x86-efistub-perform-4-5-level-paging-switch-from-the-stub.patch
queue-6.1/x86-entry_32-add-verw-just-before-userspace-transition.patch
queue-6.1/x86-boot-rename-conflicting-boot_params-pointer-to-boot_params_ptr.patch
queue-6.1/x86-efistub-perform-snp-feature-test-while-running-in-the-firmware.patch
queue-6.1/x86-efistub-simplify-and-clean-up-handover-entry-code.patch
queue-6.1/efi-libstub-add-memory-attribute-protocol-definitions.patch
queue-6.1/x86-entry_64-add-verw-just-before-userspace-transition.patch
queue-6.1/efi-libstub-add-limit-argument-to-efi_random_alloc.patch
queue-6.1/efi-x86-fix-the-missing-kaslr_flag-bit-in-boot_params-hdr.loadflags.patch
queue-6.1/kvm-vmx-use-bt-jnc-i.e.-eflags.cf-to-select-vmresume-vs.-vmlaunch.patch
queue-6.1/arm64-efi-limit-allocations-to-48-bit-addressable-physical-region.patch
queue-6.1/x86-efistub-prefer-efi-memory-attributes-protocol-over-dxe-services.patch
queue-6.1/efi-efivars-prevent-double-registration.patch
queue-6.1/x86-boot-efistub-assign-global-boot_params-variable.patch
queue-6.1/x86-efistub-clear-bss-in-efi-handover-protocol-entrypoint.patch
queue-6.1/x86-decompressor-factor-out-kernel-decompression-and-relocation.patch
queue-6.1/efi-x86-avoid-physical-kaslr-on-older-dell-systems.patch
queue-6.1/x86-bugs-add-asm-helpers-for-executing-verw.patch
