On 2017/12/06 05:32, Radim Krčmář wrote:
2017-12-01 10:21-0800, Jim Mattson:
From: Andrew Honig <ahonig@xxxxxxxxxx>
This fixes CVE-2017-1000407.
KVM allows guests to directly access I/O port 0x80 on Intel hosts. If
the guest floods this port with writes it generates exceptions and
instability in the host kernel, leading to a crash. With this change
guest writes to port 0x80 on Intel will behave the same as they
currently behave on AMD systems.
Prevent the flooding by removing the code that sets port 0x80 as a
passthrough port. This is essentially the same as upstream patch
99f85a28a78e96d28907fe036e1671a218fee597, except that patch was
for AMD chipsets and this patch is for Intel.
Signed-off-by: Andrew Honig <ahonig@xxxxxxxxxx>
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
Reviewed-by: Quan Xu <quan.xu0@xxxxxxxxx>
Quan
Alibaba Cloud
Fixes: fdef3ad1b386 ("KVM: VMX: Enable io bitmaps to avoid IO port 0x80 VMEXITs")
Cc: <stable@xxxxxxxxxxxxxxx>
Applied, thanks. The commit that introduced it boasted 3-5% performance
improvements when compiling the kernel -- have you noticed regressions?
