diff options
| author | Jim Mattson <jmattson@google.com> | 2023-08-30 21:32:21 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-08-31 23:29:49 +0200 |
| commit | 18032b47adf1db7b7f5fb2d1344e65aafe6417df (patch) | |
| tree | 7847bbd9a68b4544ebd74c07a5e2f5d7c210c0a0 | |
| parent | d87e89c2735772fbed933be0d19e032c1910a51f (diff) | |
| download | linux-18032b47adf1db7b7f5fb2d1344e65aafe6417df.tar.gz | |
x86/fpu/xstate: Fix PKRU covert channel
When XCR0[9] is set, PKRU can be read and written from userspace with
XSAVE and XRSTOR, even when CR4.PKE is clear.
Clear XCR0[9] when protection keys are disabled.
Reported-by: Tavis Ormandy <taviso@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20230831043228.1194256-1-jmattson@google.com
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 1afbc4866b1009..a27b4f7b93651d 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -71,7 +71,7 @@ static unsigned short xsave_cpuid_features[] __initdata = { [XFEATURE_ZMM_Hi256] = X86_FEATURE_AVX512F, [XFEATURE_Hi16_ZMM] = X86_FEATURE_AVX512F, [XFEATURE_PT_UNIMPLEMENTED_SO_FAR] = X86_FEATURE_INTEL_PT, - [XFEATURE_PKRU] = X86_FEATURE_PKU, + [XFEATURE_PKRU] = X86_FEATURE_OSPKE, [XFEATURE_PASID] = X86_FEATURE_ENQCMD, [XFEATURE_XTILE_CFG] = X86_FEATURE_AMX_TILE, [XFEATURE_XTILE_DATA] = X86_FEATURE_AMX_TILE, |