lkml.org 
[lkml]   [2019]   [Dec]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.4 071/162] KVM: x86: fix out-of-bounds write in KVM_GET_EMULATED_CPUID (CVE-2019-19332)
Date
From: Paolo Bonzini <pbonzini@redhat.com>

commit 433f4ba1904100da65a311033f17a9bf586b287e upstream.

The bounds check was present in KVM_GET_SUPPORTED_CPUID but not
KVM_GET_EMULATED_CPUID.

Reported-by: syzbot+e3f4897236c4eeb8af4f@syzkaller.appspotmail.com
Fixes: 84cffe499b94 ("kvm: Emulate MOVBE", 2013-10-29)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/kvm/cpuid.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -373,7 +373,7 @@ static inline int __do_cpuid_ent(struct

r = -E2BIG;

- if (*nent >= maxnent)
+ if (WARN_ON(*nent >= maxnent))
goto out;

do_cpuid_1_ent(entry, function, index);
@@ -669,6 +669,9 @@ out:
static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
u32 idx, int *nent, int maxnent, unsigned int type)
{
+ if (*nent >= maxnent)
+ return -E2BIG;
+
if (type == KVM_GET_EMULATED_CPUID)
return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);


\
 
 \ /
  Last update: 2019-12-19 20:11    [W:0.548 / U:1.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site