From: René Scharfe Date: Tue, 20 Aug 2013 20:34:10 GMT Subject: Re: CPPCheck found 24 high risk bugs in Git v.1.8.3.4 Message-ID: <5213D2C2.6090006@web.de> In-Reply-To: <87eh9op5gq.fsf@igel.home> Am 20.08.2013 20:44, schrieb Andreas Schwab: > Erik Faye-Lund writes: > >> diff --git a/compat/win32/syslog.c b/compat/win32/syslog.c >> index d015e43..0641f4e 100644 >> --- a/compat/win32/syslog.c >> +++ b/compat/win32/syslog.c >> @@ -43,11 +43,14 @@ void syslog(int priority, const char *fmt, ...) >> va_end(ap); >> >> while ((pos = strstr(str, "%1")) != NULL) { >> - str = realloc(str, ++str_len + 1); >> - if (!str) { >> + char *tmp = realloc(str, ++str_len + 1); >> + if (!tmp) { >> warning("realloc failed: '%s'", strerror(errno)); >> + free(str); >> return; >> } >> + pos = tmp + (pos - str); > > Pedantically, this is undefined (uses of both pos and str may trap after > realloc has freed the original pointer), it is better to calculate the > difference before calling realloc. And while at it, perhaps it's better to follow the suggestion in http://msdn.microsoft.com/en-us/library/aa363679.aspx under Remarks and replace "%1" with "%1!S!" instead of "% 1". René