xen/CVE-2016-1922-qemuu-i386-null-pointer-dereference-in-vapic_write.patch
Charles Arnold 95d1280885 - bsc#962321 - VUL-0: CVE-2016-1922: xen: i386: null pointer
dereference in vapic_write()
  CVE-2016-1922-qemuu-i386-null-pointer-dereference-in-vapic_write.patch
  CVE-2016-2391-qemut-usb-null-pointer-dereference-in-ohci-module.patch
- bsc#965112 - VUL-0: CVE-2014-3640: xen: slirp: NULL pointer deref
  in sosendto()
  CVE-2014-3640-qemut-slirp-NULL-pointer-deref-in-sosendto.patch

OBS-URL: https://build.opensuse.org/package/show/Virtualization/xen?expand=0&rev=404
2016-03-01 21:45:58 +00:00

62 lines
2.1 KiB
Diff

References: bsc#962321 CVE-2016-1922
Subject: i386: avoid null pointer dereference
From: P J P ppandit@redhat.com Fri Dec 18 11:35:07 2015 +0530
Date: Fri Jan 15 18:58:01 2016 +0100:
Git: 4c1396cb576c9b14425558b73de1584c7a9735d7
Hello,
A null pointer dereference issue was reported by Mr Ling Liu, CC'd here. It
occurs while doing I/O port write operations via hmp interface. In that,
'current_cpu' remains null as it is not called from cpu_exec loop, which
results in the said issue.
Below is a proposed (tested)patch to fix this issue; Does it look okay?
===
From ae88a4947fab9a148cd794f8ad2d812e7f5a1d0f Mon Sep 17 00:00:00 2001
From: Prasad J Pandit <pjp@fedoraproject.org>
Date: Fri, 18 Dec 2015 11:16:07 +0530
Subject: [PATCH] i386: avoid null pointer dereference
When I/O port write operation is called from hmp interface,
'current_cpu' remains null, as it is not called from cpu_exec()
loop. This leads to a null pointer dereference in vapic_write
routine. Add check to avoid it.
Reported-by: Ling Liu <liuling-it@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-Id: <alpine.LFD.2.20.1512181129320.9805@wniryva>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: P J P <ppandit@redhat.com>
Index: xen-4.6.1-testing/tools/qemu-xen-dir-remote/hw/i386/kvmvapic.c
===================================================================
--- xen-4.6.1-testing.orig/tools/qemu-xen-dir-remote/hw/i386/kvmvapic.c
+++ xen-4.6.1-testing/tools/qemu-xen-dir-remote/hw/i386/kvmvapic.c
@@ -634,13 +634,18 @@ static int vapic_prepare(VAPICROMState *
static void vapic_write(void *opaque, hwaddr addr, uint64_t data,
unsigned int size)
{
- CPUState *cs = current_cpu;
- X86CPU *cpu = X86_CPU(cs);
- CPUX86State *env = &cpu->env;
- hwaddr rom_paddr;
VAPICROMState *s = opaque;
+ X86CPU *cpu;
+ CPUX86State *env;
+ hwaddr rom_paddr;
+
+ if (!current_cpu) {
+ return;
+ }
- cpu_synchronize_state(cs);
+ cpu_synchronize_state(current_cpu);
+ cpu = X86_CPU(current_cpu);
+ env = &cpu->env;
/*
* The VAPIC supports two PIO-based hypercalls, both via port 0x7E.