diff options
Diffstat (limited to 'system/xen/patches/xsa172.patch')
| -rw-r--r-- | system/xen/patches/xsa172.patch | 39 |
1 files changed, 0 insertions, 39 deletions
diff --git a/system/xen/patches/xsa172.patch b/system/xen/patches/xsa172.patch deleted file mode 100644 index 8b1d01fa8449f..0000000000000 --- a/system/xen/patches/xsa172.patch +++ /dev/null @@ -1,39 +0,0 @@ -x86: fix information leak on AMD CPUs - -The fix for XSA-52 was wrong, and so was the change synchronizing that -new behavior to the FXRSTOR logic: AMD's manuals explictly state that -writes to the ES bit are ignored, and it instead gets calculated from -the exception and mask bits (it gets set whenever there is an unmasked -exception, and cleared otherwise). Hence we need to follow that model -in our workaround. - -This is XSA-172. - -The first hunk (xen/arch/x86/i387.c:fpu_fxrstor) is CVE-2016-3159. -The second hunk (xen/arch/x86/xstate.c:xrstor) is CVE-2016-3158. - -Signed-off-by: Jan Beulich <jbeulich@suse.com> -Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> - ---- a/xen/arch/x86/i387.c -+++ b/xen/arch/x86/i387.c -@@ -49,7 +49,7 @@ static inline void fpu_fxrstor(struct vc - * sometimes new user value. Both should be ok. Use the FPU saved - * data block as a safe address because it should be in L1. - */ -- if ( !(fpu_ctxt->fsw & 0x0080) && -+ if ( !(fpu_ctxt->fsw & ~fpu_ctxt->fcw & 0x003f) && - boot_cpu_data.x86_vendor == X86_VENDOR_AMD ) - { - asm volatile ( "fnclex\n\t" ---- a/xen/arch/x86/xstate.c -+++ b/xen/arch/x86/xstate.c -@@ -344,7 +344,7 @@ void xrstor(struct vcpu *v, uint64_t mas - * data block as a safe address because it should be in L1. - */ - if ( (mask & ptr->xsave_hdr.xstate_bv & XSTATE_FP) && -- !(ptr->fpu_sse.fsw & 0x0080) && -+ !(ptr->fpu_sse.fsw & ~ptr->fpu_sse.fcw & 0x003f) && - boot_cpu_data.x86_vendor == X86_VENDOR_AMD ) - asm volatile ( "fnclex\n\t" /* clear exceptions */ - "ffree %%st(7)\n\t" /* clear stack tag */ |