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| author | Jan Beulich <jbeulich@suse.com> | 2013-06-04 09:29:07 +0200 |
|---|---|---|
| committer | Jan Beulich <jbeulich@suse.com> | 2013-06-04 09:29:07 +0200 |
| commit | 365c95f7de789e1dca03f119eab7dc61fe0f77c9 (patch) | |
| tree | 49b15e15658f7efdf5327e669ad1f0f1ba8393cd | |
| parent | c6ae65db36b98f2866f74a9a7ae6ac5d51fedc67 (diff) | |
| download | xen-365c95f7de789e1dca03f119eab7dc61fe0f77c9.tar.gz xen-365c95f7de789e1dca03f119eab7dc61fe0f77c9.tar.bz2 xen-365c95f7de789e1dca03f119eab7dc61fe0f77c9.zip | |
x86/xsave: properly check guest input to XSETBV
Other than the HVM emulation path, the PV case so far failed to check
that YMM state requires SSE state to be enabled, allowing for a #GP to
occur upon passing the inputs to XSETBV inside the hypervisor.
This is CVE-2013-2078 / XSA-54.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
| -rw-r--r-- | xen/arch/x86/traps.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c index 087bbebf5f..ef964c3e39 100644 --- a/xen/arch/x86/traps.c +++ b/xen/arch/x86/traps.c @@ -2205,6 +2205,11 @@ static int emulate_privileged_op(struct cpu_user_regs *regs) if ( !(new_xfeature & XSTATE_FP) || (new_xfeature & ~xfeature_mask) ) goto fail; + /* YMM state takes SSE state as prerequisite. */ + if ( (xfeature_mask & new_xfeature & XSTATE_YMM) && + !(new_xfeature & XSTATE_SSE) ) + goto fail; + v->arch.xcr0 = new_xfeature; v->arch.xcr0_accum |= new_xfeature; set_xcr0(new_xfeature); |