# [PATCH] win32: plug memory leak on realloc() failure in syslog() 2 messages from 2017-08-10 to 2017-08-14. Participants: René Scharfe, Johannes Schindelin. Thread: https://gitlist.dev/t/46555 ## René Scharfe, 2017-08-10 10:23 Subject: [PATCH] win32: plug memory leak on realloc() failure in syslog() Message-ID: <245410ce-1f4c-f2a9-fd8d-98ff2d2c0335@web.de> URL: https://gitlist.dev/e/245410ce-1f4c-f2a9-fd8d-98ff2d2c0335%40web.de ``` If realloc() fails then the original buffer is still valid. Free it before exiting the function. Signed-off-by: Rene Scharfe --- compat/win32/syslog.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/compat/win32/syslog.c b/compat/win32/syslog.c index 6c7c9b6053..161978d720 100644 --- a/compat/win32/syslog.c +++ b/compat/win32/syslog.c @@ -43,8 +43,10 @@ void syslog(int priority, const char *fmt, ...) va_end(ap); while ((pos = strstr(str, "%1")) != NULL) { + char *oldstr = str; str = realloc(str, st_add(++str_len, 1)); if (!str) { + free(oldstr); warning_errno("realloc failed"); return; } -- 2.14.0 ``` ## Johannes Schindelin, 2017-08-14 20:26 Subject: Re: [PATCH] win32: plug memory leak on realloc() failure in syslog() Message-ID: URL: https://gitlist.dev/e/alpine.DEB.2.21.1.1708142225330.19382%40virtualbox In-Reply-To: <245410ce-1f4c-f2a9-fd8d-98ff2d2c0335@web.de> ``` Hi René, On Thu, 10 Aug 2017, René Scharfe wrote: > If realloc() fails then the original buffer is still valid. Free it > before exiting the function. > > Signed-off-by: Rene Scharfe The subject had me worried for a second... The realloc() fails so rarely that I, for one, have never encountered that problem. Still, it is a correct fix for a real bug. Thanks, Dscho ```