1 files changed, 103 insertions, 0 deletions

diff --git a/meta-oe/recipes-extended/rsyslog/rsyslog/0001-remove-memleak-introduced-by-GenerateLocalHostName-H.patch b/meta-oe/recipes-extended/rsyslog/rsyslog/0001-remove-memleak-introduced-by-GenerateLocalHostName-H.patch
new file mode 100644
index 000000000..fcc5d8ebf
--- /dev/null
+++ b/meta-oe/recipes-extended/rsyslog/rsyslog/0001-remove-memleak-introduced-by-GenerateLocalHostName-H.patch
@@ -0,0 +1,103 @@
+From 17e1ee2539cea6bac16832b488afd52b20a348ac Mon Sep 17 00:00:00 2001
+From: Rainer Gerhards <rgerhards@adiscon.com>
+Date: Mon, 28 Oct 2013 14:17:56 +0100
+Subject: [PATCH] remove memleak introduced by GenerateLocalHostName HUP
+ bugfix
+
+Upstream-Status: backport
+
+Signed-off-by: Li Zhou <li.zhou@windriver.com>
+---
+ runtime/glbl.c |   45 ++++++++++++++++++++++++++++++++-------------
+ 1 file changed, 32 insertions(+), 13 deletions(-)
+
+diff --git a/runtime/glbl.c b/runtime/glbl.c
+index bcb3795..41d56c2 100644
+--- a/runtime/glbl.c
++++ b/runtime/glbl.c
+@@ -72,6 +72,7 @@ static int option_DisallowWarning = 1;        /* complain if message from disallowed se
+ static int bDisableDNS = 0; /* don't look up IP addresses of remote messages */
+ static prop_t *propLocalIPIF = NULL;/* IP address to report for the local host (default is 127.0.0.1) */
+ static prop_t *propLocalHostName = NULL;/* our hostname as FQDN - read-only after startup */
++static prop_t *propLocalHostNameToDelete = NULL;/* see GenerateLocalHostName function hdr comment! */
+ static uchar *LocalHostName = NULL;/* our hostname  - read-only after startup, except HUP */
+ static uchar *LocalHostNameOverride = NULL;/* user-overridden hostname - read-only after startup */
+ static uchar *LocalFQDNName = NULL;/* our hostname as FQDN - read-only after startup, except HUP */
+@@ -380,24 +381,31 @@ GetLocalDomain(void)
+ /* generate the local hostname property. This must be done after the hostname info
+  * has been set as well as PreserveFQDN.
+  * rgerhards, 2009-06-30
+- * NOTE: This function DELIBERATELY introduces a small memory leak in order to gain
+- * speed. Each time it is called when a property name already exists, a new one is
+- * allocated but the previous one is NOT freed. This is so that current readers can
+- * continue to use the previous name. Otherwise, we would need to use read/write locks
+- * to protect the update process. As this function is called extremely infrequently and
+- * the memory leak is very small, this is totally accessible. Think that otherwise we
+- * would need to place a read look each time the property is read, which is much more
+- * frequent (once per message for the modules that use this local hostname!).
++ * NOTE: This function tries to avoid locking by not destructing the previous value
++ * immediately. This is so that current readers can  continue to use the previous name.
++ * Otherwise, we would need to use read/write locks to protect the update process.
++ * In order to do so, we save the previous value and delete it when we are called again
++ * the next time. Note that this in theory is racy and can lead to a double-free.
++ * In practice, however, the window of exposure to trigger this is extremely short
++ * and as this functions is very infrequently being called (on HUP), the trigger
++ * condition for this bug is so highly unlikely that it never occurs in practice.
++ * Probably if you HUP rsyslog every few milliseconds, but who does that...
++ * To further reduce risk potential, we do only update the property when there
++ * actually is a hostname change, which makes it even less likely.
+  * rgerhards, 2013-10-28
+  */
+ static rsRetVal
+ GenerateLocalHostNameProperty(void)
+ {
++       uchar *pszPrev;
++       int lenPrev;
+        prop_t *hostnameNew;
+        uchar *pszName;
+        DEFiRet;
+ 
+-       CHKiRet(prop.Construct(&hostnameNew));
++       if(propLocalHostNameToDelete != NULL)
++               prop.Destruct(&propLocalHostNameToDelete);
++
+        if(LocalHostNameOverride == NULL) {
+                if(LocalHostName == NULL)
+                        pszName = (uchar*) "[localhost]";
+@@ -411,11 +419,20 @@ GenerateLocalHostNameProperty(void)
+                pszName = LocalHostNameOverride;
+        }
+        DBGPRINTF("GenerateLocalHostName uses '%s'\n", pszName);
+-       CHKiRet(prop.SetString(hostnameNew, pszName, ustrlen(pszName)));
+-       CHKiRet(prop.ConstructFinalize(hostnameNew));
+ 
+-       propLocalHostName = hostnameNew;
+-       /* inititional MEM LEAK for old value -- see function hdr comment! */
++       if(propLocalHostName == NULL)
++               pszPrev = (uchar*)""; /* make sure strcmp() below does not match */
++       else
++               prop.GetString(propLocalHostName, &pszPrev, &lenPrev);
++
++       if(ustrcmp(pszPrev, pszName)) {
++               /* we need to update */
++               CHKiRet(prop.Construct(&hostnameNew));
++               CHKiRet(prop.SetString(hostnameNew, pszName, ustrlen(pszName)));
++               CHKiRet(prop.ConstructFinalize(hostnameNew));
++               propLocalHostNameToDelete = propLocalHostName;
++               propLocalHostName = hostnameNew;
++       }
+ 
+ finalize_it:
+        RETiRet;
+@@ -678,6 +695,8 @@ BEGINObjClassExit(glbl, OBJ_IS_CORE_MODULE) /* class, version */
+        free(LocalHostNameOverride);
+        free(LocalFQDNName);
+        objRelease(prop, CORE_COMPONENT);
++       if(propLocalHostNameToDelete != NULL)
++               prop.Destruct(&propLocalHostNameToDelete);
+        DESTROY_ATOMIC_HELPER_MUT(mutTerminateInputs);
+ ENDObjClassExit(glbl)
+ 
+-- 
+1.7.9.5
+