commit ea976e8743ad3b3263faae00d88e40bcf727097d
from: Omar Polo <op@omarpolo.com>
date: Tue Jul 06 10:48:59 2021 UTC

don't let CGI scripts inherit our stderr

our stderr could have been sent to the logger process, so it may be
invalid.  Furthermore, in the future we may want to capture also the
stderr of the processes.

commit - ef945cf4157bc8239c6da682a89ba60b11cc0e26
commit + ea976e8743ad3b3263faae00d88e40bcf727097d
blob - 1868156747dbd6b76fde440953f1256f5cf35312
blob + 8e25bd13254a1e570f1f8a04f3fc9ca2bb721b73
--- ex.c
+++ ex.c
@@ -128,10 +128,12 @@ static int
 launch_cgi(struct iri *iri, struct cgireq *req, struct vhost *vhost,
     struct location *loc)
 {
-	int p[2];		/* read end, write end */
+	int p[2], errp[2];	/* read end, write end */
 
 	if (pipe(p) == -1)
 		return -1;
+	if (pipe(errp) == -1)
+		return -1;
 
 	switch (fork()) {
 	case -1:
@@ -147,6 +149,10 @@ launch_cgi(struct iri *iri, struct cgireq *req, struct
 		if (dup2(p[1], 1) == -1)
 			goto childerr;
 
+		close(errp[0]);
+		if (dup2(errp[1], 2) == -1)
+			goto childerr;
+
 		ex = xasprintf("%s/%s", loc->dir, req->spath);
 
 		serialize_iri(iri, iribuf, sizeof(iribuf));
@@ -224,6 +230,7 @@ launch_cgi(struct iri *iri, struct cgireq *req, struct
 
 	default:
 		close(p[1]);
+		close(errp[1]);
 		mark_nonblock(p[0]);
 		return p[0];
 	}