Package: perl
Version: 5.20.2-3+deb8u9
Severity: important
Tags: upstream patch
Dear Maintainer,
Sys::Syslog module is not thread-safe, reopening syslog connection
(could be internal/automatic after transient transport error, without user
calling openlog/closelog) can crash multithreaded process
(Apache event MPM with mod_perl in my case).
You can find upstream bug report at
https://rt.perl.org/Public/Bug/Display.html?id=132679 ,
attached patch (serializing access to shared variable with straightforward
locking)
has been tested on jessie.
-- System Information:
Debian Release: 8.10
APT prefers oldstable-updates
APT policy: (860, 'oldstable-updates'), (850, 'oldstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Init: systemd (via /run/systemd/system)
Versions of packages perl depends on:
ii dpkg 1.17.27
ii libbz2-1.0 1.0.6-7+b3
ii libc6 2.19-18+deb8u10
ii libdb5.3 5.3.28-9+deb8u1
ii libgdbm3 1.8.3-13.1
ii perl-base 5.20.2-3+deb8u9
ii perl-modules 5.20.2-3+deb8u9
ii zlib1g 1:1.2.8.dfsg-2+b1
Versions of packages perl recommends:
ii netbase 5.3
ii rename 0.20-3
Versions of packages perl suggests:
pn libterm-readline-gnu-perl | libterm-readline-perl-perl <none>
ii make 4.0-8.1
ii perl-doc 5.20.2-3+deb8u9
-- no debconf information
Index: perl-5.20.2/cpan/Sys-Syslog/Syslog.xs
===================================================================
--- perl-5.20.2.orig/cpan/Sys-Syslog/Syslog.xs
+++ perl-5.20.2/cpan/Sys-Syslog/Syslog.xs
@@ -31,6 +31,9 @@
static SV *ident_svptr;
+#ifdef USE_ITHREADS
+STATIC perl_mutex ident_mutex;
+#endif
#ifndef LOG_FAC
#define LOG_FACMASK 0x03f8
@@ -102,9 +105,21 @@ openlog_xs(ident, option, facility)
STRLEN len;
char* ident_pv;
CODE:
+#ifdef USE_ITHREADS
+ MUTEX_LOCK(&ident_mutex);
+#endif
+ if (ident_svptr) {
+ closelog();
+ SvREFCNT_dec(ident_svptr);
+ ident_svptr = NULL;
+ }
ident_svptr = newSVsv(ident);
ident_pv = SvPV(ident_svptr, len);
openlog(ident_pv, option, facility);
+#ifdef USE_ITHREADS
+ MUTEX_UNLOCK(&ident_mutex);
+#endif
+
void
syslog_xs(priority, message)
@@ -128,15 +143,25 @@ closelog_xs()
PREINIT:
U32 refcnt;
CODE:
- if (!ident_svptr)
- return;
- closelog();
- refcnt = SvREFCNT(ident_svptr);
- if (refcnt) {
- SvREFCNT_dec(ident_svptr);
- if (refcnt == 1)
+#ifdef USE_ITHREADS
+ MUTEX_LOCK(&ident_mutex);
+#endif
+ if (ident_svptr) {
+ closelog();
+ SvREFCNT_dec(ident_svptr);
ident_svptr = NULL;
}
+#ifdef USE_ITHREADS
+ MUTEX_UNLOCK(&ident_mutex);
+#endif
+
+BOOT:
+{
+#ifdef USE_ITHREADS
+ MUTEX_INIT(&ident_mutex);
+#endif
+ ident_svptr = 0;
+}
#else /* HAVE_SYSLOG */
