Accepting request 575801 from home:cbosdonnat:branches:Virtualization

Add fix for the CVE fix
   c2dc6698-fix-deadlock-obtaining-hostname.patch

OBS-URL: https://build.opensuse.org/request/show/575801
OBS-URL: https://build.opensuse.org/package/show/Virtualization/libvirt?expand=0&rev=668
This commit is contained in:
Cédric Bosdonnat 2018-02-12 14:39:51 +00:00 committed by Git OBS Bridge
parent 63dfdb29d7
commit 3b296fe76b
3 changed files with 124 additions and 0 deletions

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@ -0,0 +1,121 @@
From c2dc6698c88fb591639e542c8ecb0076c54f3dfb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
Date: Mon, 12 Feb 2018 10:03:08 +0000
Subject: [PATCH] log: fix deadlock obtaining hostname (related CVE-2018-6764)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
The fix for CVE-2018-6764 introduced a potential deadlock scenario
that gets triggered by the NSS module when virGetHostname() calls
getaddrinfo to resolve the hostname:
#0 0x00007f6e714b57e7 in futex_wait
#1 futex_wait_simple
#2 __pthread_once_slow
#3 0x00007f6e71d16e7d in virOnce
#4 0x00007f6e71d0997c in virLogInitialize
#5 0x00007f6e71d0a09a in virLogVMessage
#6 0x00007f6e71d09ffd in virLogMessage
#7 0x00007f6e71d0db22 in virObjectNew
#8 0x00007f6e71d0dbf1 in virObjectLockableNew
#9 0x00007f6e71d0d3e5 in virMacMapNew
#10 0x00007f6e71cdc50a in findLease
#11 0x00007f6e71cdcc56 in _nss_libvirt_gethostbyname4_r
#12 0x00007f6e724631fc in gaih_inet
#13 0x00007f6e72464697 in __GI_getaddrinfo
#14 0x00007f6e71d19e81 in virGetHostnameImpl
#15 0x00007f6e71d1a057 in virGetHostnameQuiet
#16 0x00007f6e71d09936 in virLogOnceInit
#17 0x00007f6e71d09952 in virLogOnce
#18 0x00007f6e714b5829 in __pthread_once_slow
#19 0x00007f6e71d16e7d in virOnce
#20 0x00007f6e71d0997c in virLogInitialize
#21 0x00007f6e71d0a09a in virLogVMessage
#22 0x00007f6e71d09ffd in virLogMessage
#23 0x00007f6e71d0db22 in virObjectNew
#24 0x00007f6e71d0dbf1 in virObjectLockableNew
#25 0x00007f6e71d0d3e5 in virMacMapNew
#26 0x00007f6e71cdc50a in findLease
#27 0x00007f6e71cdc839 in _nss_libvirt_gethostbyname3_r
#28 0x00007f6e71cdc724 in _nss_libvirt_gethostbyname2_r
#29 0x00007f6e7248f72f in __gethostbyname2_r
#30 0x00007f6e7248f494 in gethostbyname2
#31 0x000056348c30c36d in hosts_keys
#32 0x000056348c30b7d2 in main
Fortunately the extra stuff virGetHostname does is totally irrelevant to
the needs of the logging code, so we can just inline a call to the
native hostname() syscall directly.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
cfg.mk | 2 +-
src/util/virlog.c | 20 ++++++++++++++------
2 files changed, 15 insertions(+), 7 deletions(-)
Index: libvirt-4.0.0/cfg.mk
===================================================================
--- libvirt-4.0.0.orig/cfg.mk
+++ libvirt-4.0.0/cfg.mk
@@ -1183,7 +1183,7 @@ _src2=src/(util/vircommand|libvirt|lxc/l
exclude_file_name_regexp--sc_prohibit_fork_wrappers = \
(^($(_src2)|tests/testutils|daemon/libvirtd)\.c$$)
-exclude_file_name_regexp--sc_prohibit_gethostname = ^src/util/virutil\.c$$
+exclude_file_name_regexp--sc_prohibit_gethostname = ^src/util/vir(util|log)\.c$$
exclude_file_name_regexp--sc_prohibit_internal_functions = \
^src/(util/(viralloc|virutil|virfile)\.[hc]|esx/esx_vi\.c)$$
Index: libvirt-4.0.0/src/util/virlog.c
===================================================================
--- libvirt-4.0.0.orig/src/util/virlog.c
+++ libvirt-4.0.0/src/util/virlog.c
@@ -64,7 +64,7 @@
VIR_LOG_INIT("util.log");
static regex_t *virLogRegex;
-static char *virLogHostname;
+static char virLogHostname[HOST_NAME_MAX+1];
#define VIR_LOG_DATE_REGEX "[0-9]{4}-[0-9]{2}-[0-9]{2}"
@@ -261,6 +261,8 @@ virLogPriorityString(virLogPriority lvl)
static int
virLogOnceInit(void)
{
+ int r;
+
if (virMutexInit(&virLogMutex) < 0)
return -1;
@@ -275,8 +277,17 @@ virLogOnceInit(void)
/* We get and remember the hostname early, because at later time
* it might not be possible to load NSS modules via getaddrinfo()
* (e.g. at container startup the host filesystem will not be
- * accessible anymore. */
- virLogHostname = virGetHostnameQuiet();
+ * accessible anymore.
+ * Must not use virGetHostname though as that causes re-entrancy
+ * problems if it triggers logging codepaths
+ */
+ r = gethostname(virLogHostname, sizeof(virLogHostname));
+ if (r == -1) {
+ ignore_value(virStrcpy(virLogHostname,
+ "(unknown)", sizeof(virLogHostname)));
+ } else {
+ NUL_TERMINATE(virLogHostname);
+ }
virLogUnlock();
return 0;
@@ -475,9 +486,6 @@ virLogHostnameString(char **rawmsg,
{
char *hoststr;
- if (!virLogHostname)
- return -1;
-
if (virAsprintfQuiet(&hoststr, "hostname: %s", virLogHostname) < 0) {
return -1;
}

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@ -7,6 +7,7 @@ Fri Feb 9 13:28:14 UTC 2018 - cbosdonnat@suse.com
- Determine hostname early to avoid code injection
in lxc driver. (bsc#1080042)
759b4d1b-virlog-determine-the-hostname-on-startup-CVE-2018-67.patch
c2dc6698-fix-deadlock-obtaining-hostname.patch
- Add basic support of connectGetAllDomainStats for lxc driver
(fate#323742)
0001-Extract-stats-functions-from-the-qemu-driver.patch

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@ -324,6 +324,7 @@ Patch3: 76977061-qemu-smbios-oem-strings.patch
Patch4: 0c710a37-libxl-resume-lock-on-mig-failure.patch
Patch5: 6b3d716e-keycodemap-py3.patch
Patch6: 759b4d1b-virlog-determine-the-hostname-on-startup-CVE-2018-67.patch
Patch7: c2dc6698-fix-deadlock-obtaining-hostname.patch
# Patches pending upstream review
Patch100: libxl-dom-reset.patch
Patch101: network-don-t-use-dhcp-authoritative-on-static-netwo.patch
@ -922,6 +923,7 @@ pushd src/keycodemapdb
%patch5 -p1
popd
%patch6 -p1
%patch7 -p1
%patch100 -p1
%patch101 -p1
%patch150 -p1