From: Rich Felker <dalias@aerifal.cx>
Date: Wed, 20 Jun 2012 18:32:48 +0000 (-0400)
Subject: popen: handle issues with fd0/1 being closed
X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=commitdiff_plain;h=f305467aad4659e92fff84be6c89d4767b6f99d4

popen: handle issues with fd0/1 being closed

also check for failure of dup2 and abort the child rather than
reading/writing the wrong file.
---

diff --git a/src/stdio/popen.c b/src/stdio/popen.c
index 1d33e9d6..50765daa 100644
--- a/src/stdio/popen.c
+++ b/src/stdio/popen.c
@@ -31,9 +31,9 @@ FILE *popen(const char *cmd, const char *mode)
 		close(p[1]);
 		return NULL;
 	case 0:
-		dup2(p[1-op], 1-op);
-		close(p[0]);
-		close(p[1]);
+		if (dup2(p[1-op], 1-op) < 0) _exit(127);
+		if (p[0] != 1-op) close(p[0]);
+		if (p[1] != 1-op) close(p[1]);
 		execl("/bin/sh", "sh", "-c", cmd, (char *)0);
 		_exit(127);
 	}