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| author | Xiaotian Feng <dfeng@redhat.com> | 2010-08-13 15:19:11 +0800 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-08-15 14:10:15 +0300 |
| commit | f45755b8346f1a089ca7957dce5f4c3c6cb26e6f (patch) | |
| tree | f0b34312371aeaf88fed462857af0630a2c19af8 /arch/x86 | |
| parent | 3cfc2c42c1cbc8e238bb9c0612c0df4565e3a8b4 (diff) | |
| download | linux-f45755b8346f1a089ca7957dce5f4c3c6cb26e6f.tar.gz | |
KVM: fix poison overwritten caused by using wrong xstate size
fpu.state is allocated from task_xstate_cachep, the size of task_xstate_cachep
is xstate_size. xstate_size is set from cpuid instruction, which is often
smaller than sizeof(struct xsave_struct). kvm is using sizeof(struct xsave_struct)
to fill in/out fpu.state.xsave, as what we allocated for fpu.state is
xstate_size, kernel will write out of memory and caused poison/redzone/padding
overwritten warnings.
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Reviewed-by: Sheng Yang <sheng@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Sheng Yang <sheng@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/i387.c | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 4 |
2 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index c4444bce8469..f855658d2784 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -40,6 +40,7 @@ static unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu; unsigned int xstate_size; +EXPORT_SYMBOL_GPL(xstate_size); unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32); static struct i387_fxsave_struct fx_scratch __cpuinitdata; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 97aab036dabf..bb2347a69c07 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2387,7 +2387,7 @@ static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu, if (cpu_has_xsave) memcpy(guest_xsave->region, &vcpu->arch.guest_fpu.state->xsave, - sizeof(struct xsave_struct)); + xstate_size); else { memcpy(guest_xsave->region, &vcpu->arch.guest_fpu.state->fxsave, @@ -2405,7 +2405,7 @@ static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu, if (cpu_has_xsave) memcpy(&vcpu->arch.guest_fpu.state->xsave, - guest_xsave->region, sizeof(struct xsave_struct)); + guest_xsave->region, xstate_size); else { if (xstate_bv & ~XSTATE_FPSSE) return -EINVAL; |