From a0d46cded9286299f265ac993bf109b6b417dc32 Mon Sep 17 00:00:00 2001
From: Rob Swindell <rob@synchro.net>
Date: Tue, 15 Sep 2020 22:19:24 -0700
Subject: [PATCH] Resolve race condition around temp directory creation It's
possible that isdir(temp_dir) will be false and then a mkpath() call will
fail because some other thread came in and crated the directory at that very
moment - so save errno if mkdir fails and call isdir() again to double-check
that the directory wasn't created by someone else already.
---
src/sbbs3/load_cfg.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/src/sbbs3/load_cfg.c b/src/sbbs3/load_cfg.c
index 61c69d880b..ee0ecb55f8 100644
--- a/src/sbbs3/load_cfg.c
+++ b/src/sbbs3/load_cfg.c
@@ -347,8 +347,11 @@ int md(const char* inpath)
*p = '\0';
if(!isdir(path)) {
- if(mkpath(path) != 0)
- return errno;
+ if(mkpath(path) != 0) {
+ int result = errno;
+ if(!isdir(path)) // race condition: did another thread make the directory already?
+ return result;
+ }
}
return 0;
--
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