This is a note to let you know that I've just added the patch titled
KVM: x86: fix conversion of addresses to linear in 32-bit protected mode
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-x86-fix-conversion-of-addresses-to-linear-in-32-bit-protected-mode.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0c1d77f4ba5cc9c05a29adca3d6466cdf4969b70 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Date: Fri, 19 Feb 2016 18:07:21 +0100
Subject: KVM: x86: fix conversion of addresses to linear in 32-bit protected mode
From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
commit 0c1d77f4ba5cc9c05a29adca3d6466cdf4969b70 upstream.
Commit e8dd2d2d641c ("Silence compiler warning in arch/x86/kvm/emulate.c",
2015-09-06) broke boot of the Hurd. The bug is that the "default:"
case actually could modify "la", but after the patch this change is
not reflected in *linear.
The bug is visible whenever a non-zero segment base causes the linear
address to wrap around the 4GB mark.
Fixes: e8dd2d2d641cb2724ee10e76c0ad02e04289c017
Reported-by: Aurelien Jarno <aurelien@xxxxxxxxxxx>
Tested-by: Aurelien Jarno <aurelien@xxxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -650,10 +650,10 @@ static __always_inline int __linearize(s
u16 sel;
la = seg_base(ctxt, addr.seg) + addr.ea;
- *linear = la;
*max_size = 0;
switch (mode) {
case X86EMUL_MODE_PROT64:
+ *linear = la;
if (is_noncanonical_address(la))
goto bad;
@@ -662,6 +662,7 @@ static __always_inline int __linearize(s
goto bad;
break;
default:
+ *linear = la = (u32)la;
usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL,
addr.seg);
if (!usable)
@@ -689,7 +690,6 @@ static __always_inline int __linearize(s
if (size > *max_size)
goto bad;
}
- la &= (u32)-1;
break;
}
if (insn_aligned(ctxt, size) && ((la & (size - 1)) != 0))
Patches currently in stable-queue which might be from pbonzini@xxxxxxxxxx are
queue-4.4/kvm-x86-fix-conversion-of-addresses-to-linear-in-32-bit-protected-mode.patch
queue-4.4/kvm-x86-mmu-fix-ubsan-index-out-of-range-warning.patch
queue-4.4/kvm-x86-fix-missed-hardware-breakpoints.patch
queue-4.4/kvm-async_pf-do-not-warn-on-page-allocation-failures.patch
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