Messages in this thread | | | Date | Fri, 8 Jan 2021 18:20:49 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86/sev-es: Fix SEV-ES #VC handler for string port IO |
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On Thu, Jan 07, 2021 at 06:51:07PM -0800, Hyunwook (Wooky) Baek wrote: > Don't assume dest/source buffers are userspace addresses when manually > copying data for string I/O or MOVS MMIO, as {get,put}_user() will fail > if handed a kernel address and ultimately lead to a kernel panic. > > Signed-off-by: Hyunwook (Wooky) Baek <baekhw@google.com> > Acked-by: David Rientjes <rientjes@google.com> > --- > arch/x86/kernel/sev-es.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c > index 0bd1a0fc587e..812494d216ba 100644 > --- a/arch/x86/kernel/sev-es.c > +++ b/arch/x86/kernel/sev-es.c > @@ -286,6 +286,12 @@ static enum es_result vc_write_mem(struct es_em_ctxt *ctxt, > u16 d2; > u8 d1; > > + /* If instruction ran in kernel mode and the I/O buffer is in kernel space */ > + if (!user_mode(ctxt->regs) && !access_ok(s, size)) { ^^^
Just by looking at this patch I know you haven't tested it before sending.
:-(
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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