diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-03-12 09:31:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-03-12 09:31:39 -0700 |
| commit | 0e33cf955f07e3991e45109cb3e29fbc9ca51d06 (patch) | |
| tree | 334a882eb66f2a0402afee1e0cb7e31c4f40cd77 /arch/x86/Kconfig | |
| parent | 855684c7d938c2442f07eabc154e7532b4c1fbf9 (diff) | |
| parent | 2a0180129d726a4b953232175857d442651b55a0 (diff) | |
Merge tag 'rfds-for-linus-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 RFDS mitigation from Dave Hansen:
"RFDS is a CPU vulnerability that may allow a malicious userspace to
infer stale register values from kernel space. Kernel registers can
have all kinds of secrets in them so the mitigation is basically to
wait until the kernel is about to return to userspace and has user
values in the registers. At that point there is little chance of
kernel secrets ending up in the registers and the microarchitectural
state can be cleared.
This leverages some recent robustness fixes for the existing MDS
vulnerability. Both MDS and RFDS use the VERW instruction for
mitigation"
* tag 'rfds-for-linus-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
KVM/x86: Export RFDS_NO and RFDS_CLEAR to guests
x86/rfds: Mitigate Register File Data Sampling (RFDS)
Documentation/hw-vuln: Add documentation for RFDS
x86/mmio: Disable KVM mitigation when X86_FEATURE_CLEAR_CPU_BUF is set
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 8f7271d9f1d7..77e8c8c67950 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2623,6 +2623,17 @@ config MITIGATION_GDS_FORCE If in doubt, say N. +config MITIGATION_RFDS + bool "RFDS Mitigation" + depends on CPU_SUP_INTEL + default y + help + Enable mitigation for Register File Data Sampling (RFDS) by default. + RFDS is a hardware vulnerability which affects Intel Atom CPUs. It + allows unprivileged speculative access to stale data previously + stored in floating point, vector and integer registers. + See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst> + endif config ARCH_HAS_ADD_PAGES |