From 2f21b92ca5c7629ffef16e5240124dac686da08f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Deuc=D0=B5?= <shurd@sasktel.net>
Date: Mon, 12 Jun 2023 20:05:18 -0400
Subject: [PATCH] This is exactly the sort of race condition pthread_once() is
for.
---
src/sbbs3/sbbscon.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/src/sbbs3/sbbscon.c b/src/sbbs3/sbbscon.c
index a2974c0483..9083e1c1f2 100644
--- a/src/sbbs3/sbbscon.c
+++ b/src/sbbs3/sbbscon.c
@@ -316,8 +316,15 @@ static void recycle_all()
}
#ifdef __unix__
+pthread_once_t setid_mutex_once = PTHREAD_ONCE_INIT;
static pthread_mutex_t setid_mutex;
-static BOOL setid_mutex_initialized=0;
+
+static void
+init_setuid_mutex(void)
+{
+ pthread_mutex_init(&setid_mutex, NULL);
+}
+
/**********************************************************
* Change uid of the calling process to the user if specified
* **********************************************************/
@@ -334,11 +341,7 @@ static BOOL do_seteuid(BOOL to_new)
if(old_uid==new_uid && old_gid==new_gid)
return(TRUE); /* do nothing */
- if(!setid_mutex_initialized) {
- pthread_mutex_init(&setid_mutex,NULL);
- setid_mutex_initialized=TRUE;
- }
-
+ pthread_once(&setid_mutex_once, init_setuid_mutex);
pthread_mutex_lock(&setid_mutex);
if(to_new) {
@@ -383,11 +386,7 @@ BOOL do_setuid(BOOL force)
if(old_uid==new_uid && old_gid==new_gid)
return(TRUE); /* do nothing */
- if(!setid_mutex_initialized) {
- pthread_mutex_init(&setid_mutex,NULL);
- setid_mutex_initialized=TRUE;
- }
-
+ pthread_once(&setid_mutex_once, init_setuid_mutex);
pthread_mutex_lock(&setid_mutex);
if(getegid()!=old_gid) {
--
GitLab