File a7a03324-libxl-protect-logger-access.patch of Package libvirt.22291
commit a7a03324d86e111f81687b5315b8f296dde84340
Author: Jim Fehlig <jfehlig@suse.com>
Date: Thu Nov 18 12:03:20 2021 -0700
libxl: Protect access to libxlLogger files hash table
The hash table of log file objects in libxlLogger is not protected against
concurrent access. It is possible for one thread to remove an entry while
another is updating it. Add a mutex to the libxlLogger object and lock it
when accessing the files hash table.
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Index: libvirt-6.0.0/src/libxl/libxl_logger.c
===================================================================
--- libvirt-6.0.0.orig/src/libxl/libxl_logger.c
+++ libvirt-6.0.0/src/libxl/libxl_logger.c
@@ -28,6 +28,7 @@
#include "util/virfile.h"
#include "util/virhash.h"
#include "util/virstring.h"
+#include "util/virthread.h"
#include "util/virtime.h"
#define VIR_FROM_THIS VIR_FROM_LIBXL
@@ -43,6 +44,7 @@ struct xentoollog_logger_libvirt {
/* map storing the opened fds: "domid" -> FILE* */
virHashTablePtr files;
+ virMutex tableLock;
FILE *defaultLogFile;
};
@@ -86,7 +88,9 @@ libvirt_vmessage(xentoollog_logger *logg
start = start + 9;
*end = '\0';
+ virMutexLock(&lg->tableLock);
domainLogFile = virHashLookup(lg->files, start);
+ virMutexUnlock(&lg->tableLock);
if (domainLogFile)
logFile = domainLogFile;
@@ -154,9 +158,14 @@ libxlLoggerNew(const char *logDir, virLo
}
logger.logDir = logDir;
- if ((logger.files = virHashCreate(3, libxlLoggerFileFree)) == NULL)
+ if (virMutexInit(&logger.tableLock) < 0)
return NULL;
+ if ((logger.files = virHashCreate(3, libxlLoggerFileFree)) == NULL) {
+ virMutexDestroy(&logger.tableLock);
+ return NULL;
+ }
+
path = g_strdup_printf("%s/libxl-driver.log", logDir);
if ((logger.defaultLogFile = fopen(path, "a")) == NULL)
@@ -180,6 +189,7 @@ libxlLoggerFree(libxlLoggerPtr logger)
if (logger->defaultLogFile)
VIR_FORCE_FCLOSE(logger->defaultLogFile);
virHashFree(logger->files);
+ virMutexDestroy(&logger->tableLock);
xtl_logger_destroy(xtl_logger);
}
@@ -202,7 +212,9 @@ libxlLoggerOpenFile(libxlLoggerPtr logge
path, virStrerror(errno, ebuf, sizeof(ebuf)));
goto cleanup;
}
+ virMutexLock(&logger->tableLock);
ignore_value(virHashAddEntry(logger->files, domidstr, logFile));
+ virMutexUnlock(&logger->tableLock);
/* domain_config is non NULL only when starting a new domain */
if (domain_config) {
@@ -221,7 +233,9 @@ libxlLoggerCloseFile(libxlLoggerPtr logg
char *domidstr = NULL;
domidstr = g_strdup_printf("%d", id);
+ virMutexLock(&logger->tableLock);
ignore_value(virHashRemoveEntry(logger->files, domidstr));
+ virMutexUnlock(&logger->tableLock);
VIR_FREE(domidstr);
}