From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Xen-devel <xen-devel@lists.xen.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
Wei Liu <wei.liu2@citrix.com>, Jan Beulich <JBeulich@suse.com>
Subject: [PATCH for-4.8] x86/emul: Reject LGDT/LIDT attempts with non-canonical base addresses
Date: Wed, 2 Nov 2016 14:52:17 +0000 [thread overview]
Message-ID: <1478098337-13933-1-git-send-email-andrew.cooper3@citrix.com> (raw)
No sane OS would deliberately try this, but make Xen's emulation match real
hardware by delivering #GP(0), rather than suffering a VMEntry failure.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Wei Liu <wei.liu2@citrix.com>
---
xen/arch/x86/x86_emulate/x86_emulate.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c
index 7a707dc..6b940c4 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -4443,6 +4443,8 @@ x86_emulate(
(rc = read_ulong(ea.mem.seg, ea.mem.off+2,
&base, mode_64bit() ? 8 : 4, ctxt, ops)) )
goto done;
+ generate_exception_if(mode_64bit() &&
+ !is_canonical_address(base), EXC_GP, 0);
sreg.base = base;
sreg.limit = limit;
if ( op_bytes == 2 )
--
2.1.4
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next reply other threads:[~2016-11-02 14:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-02 14:52 Andrew Cooper [this message]
2016-11-02 15:42 ` [PATCH for-4.8] x86/emul: Reject LGDT/LIDT attempts with non-canonical base addresses Jan Beulich
2016-11-02 17:39 ` Andrew Cooper
2016-11-03 10:43 ` Wei Liu
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