From e58a0e9b26dc374155b90a8f42c3a5b09e8ed1f7 Mon Sep 17 00:00:00 2001
From: Nat Goodspeed <nat@lindenlab.com>
Date: Tue, 12 Jul 2011 14:34:31 -0400
Subject: [PATCH] CHOP-753: Defend against boost::regex exceptions. (per Monty
code review) Explain why we intentionally don't suppress exceptions from
boost::regex objects constructed with string literals. Catch
std::runtime_error from boost::regex_search() and boost::regex_match(); log
and return false.
---
indra/llcommon/llsys.cpp | 50 ++++++++++++++++++++++++++++++++++++----
1 file changed, 46 insertions(+), 4 deletions(-)
diff --git a/indra/llcommon/llsys.cpp b/indra/llcommon/llsys.cpp
index aa71590eae9..ebdef56c2aa 100644
--- a/indra/llcommon/llsys.cpp
+++ b/indra/llcommon/llsys.cpp
@@ -70,11 +70,13 @@ using namespace llsd;
# include <Carbon/Carbon.h>
# include <sys/wait.h>
# include <string.h>
+# include <stdexcept>
#elif LL_LINUX
# include <errno.h>
# include <sys/utsname.h>
# include <unistd.h>
# include <sys/sysinfo.h>
+# include <stdexcept>
const char MEMINFO_FILE[] = "/proc/meminfo";
#elif LL_SOLARIS
# include <stdio.h>
@@ -682,6 +684,38 @@ class StatsArray
LLSD mStats;
};
+// Wrap boost::regex_match() with a function that doesn't throw.
+template <typename S, typename M, typename R>
+static bool regex_match_no_exc(const S& string, M& match, const R& regex)
+{
+ try
+ {
+ return boost::regex_match(string, match, regex);
+ }
+ catch (const std::runtime_error& e)
+ {
+ LL_WARNS("LLMemoryInfo") << "error matching with '" << regex.str() << "': "
+ << e.what() << ":\n'" << string << "'" << LL_ENDL;
+ return false;
+ }
+}
+
+// Wrap boost::regex_search() with a function that doesn't throw.
+template <typename S, typename M, typename R>
+static bool regex_search_no_exc(const S& string, M& match, const R& regex)
+{
+ try
+ {
+ return boost::regex_search(string, match, regex);
+ }
+ catch (const std::runtime_error& e)
+ {
+ LL_WARNS("LLMemoryInfo") << "error searching with '" << regex.str() << "': "
+ << e.what() << ":\n'" << string << "'" << LL_ENDL;
+ return false;
+ }
+}
+
LLMemoryInfo::LLMemoryInfo()
{
refresh();
@@ -1012,6 +1046,10 @@ LLSD LLMemoryInfo::loadStatsArray()
// Pageouts: 41759.
// Object cache: 841598 hits of 7629869 lookups (11% hit rate)
+ // Intentionally don't pass the boost::no_except flag. These
+ // boost::regex objects are constructed with string literals, so they
+ // should be valid every time. If they become invalid, we WANT an
+ // exception, hopefully even before the dev checks in.
boost::regex pagesize_rx("\\(page size of ([0-9]+) bytes\\)");
boost::regex stat_rx("(.+): +([0-9]+)\\.");
boost::regex cache_rx("Object cache: ([0-9]+) hits of ([0-9]+) lookups "
@@ -1031,7 +1069,7 @@ LLSD LLMemoryInfo::loadStatsArray()
line[--linelen] = '\0';
}
LL_DEBUGS("LLMemoryInfo") << line << LL_ENDL;
- if (boost::regex_search(line, matched, pagesize_rx))
+ if (regex_search_no_exc(line, matched, pagesize_rx))
{
// "Mach Virtual Memory Statistics: (page size of 4096 bytes)"
std::string pagesize_str(matched[1].first, matched[1].second);
@@ -1049,7 +1087,7 @@ LLSD LLMemoryInfo::loadStatsArray()
}
stats.add("page size", pagesizekb);
}
- else if (boost::regex_match(line, matched, stat_rx))
+ else if (regex_match_no_exc(line, matched, stat_rx))
{
// e.g. "Pages free: 462078."
// Strip double-quotes off certain statistic names
@@ -1084,7 +1122,7 @@ LLSD LLMemoryInfo::loadStatsArray()
stats.add(kbkey, value * pagesizekb);
}
}
- else if (boost::regex_match(line, matched, cache_rx))
+ else if (regex_match_no_exc(line, matched, cache_rx))
{
// e.g. "Object cache: 841598 hits of 7629869 lookups (11% hit rate)"
static const char* cache_keys[] = { "cache hits", "cache lookups", "cache hit%" };
@@ -1185,6 +1223,10 @@ LLSD LLMemoryInfo::loadStatsArray()
// DirectMap4k: 434168 kB
// DirectMap2M: 477184 kB
+ // Intentionally don't pass the boost::no_except flag. This
+ // boost::regex object is constructed with a string literal, so it
+ // should be valid every time. If it becomes invalid, we WANT an
+ // exception, hopefully even before the dev checks in.
boost::regex stat_rx("(.+): +([0-9]+)( kB)?");
boost::smatch matched;
@@ -1192,7 +1234,7 @@ LLSD LLMemoryInfo::loadStatsArray()
while (std::getline(meminfo, line))
{
LL_DEBUGS("LLMemoryInfo") << line << LL_ENDL;
- if (boost::regex_match(line, matched, stat_rx))
+ if (regex_match_no_exc(line, matched, stat_rx))
{
// e.g. "MemTotal: 4108424 kB"
LLSD::String key(matched[1].first, matched[1].second);
--
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