From: Dmitry V. Levin <ldv@altlinux.org>
Date: Tue, 9 Sep 2014 22:42:12 +0000 (+0000)
Subject: decode_select: fix potential use of an uninitialized variable
X-Git-Tag: v4.10~397
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6522f132ba865f90ba3bb3a740eff191911e4dba;p=strace

decode_select: fix potential use of an uninitialized variable

A pointer to fd_set was used uninitialized when nfds == 0.

* desc.c (decode_select): Initialize fds.

Reported-by: Zubin Mithra <zubin.mithra@gmail.com>
---

diff --git a/desc.c b/desc.c
index 5b8869bc..491e9ba9 100644
--- a/desc.c
+++ b/desc.c
@@ -314,7 +314,7 @@ decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
 {
 	int i, j;
 	int nfds, fdsize;
-	fd_set *fds;
+	fd_set *fds = NULL;
 	const char *sep;
 	long arg;
 
@@ -322,10 +322,9 @@ decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
 	nfds = (int) args[0];
 
 	/* Kernel rejects negative nfds, so we don't parse it either. */
-	if (nfds < 0) {
+	if (nfds < 0)
 		nfds = 0;
-		fds = NULL;
-	}
+
 	/* Beware of select(2^31-1, NULL, NULL, NULL) and similar... */
 	if (nfds > 1024*1024)
 		nfds = 1024*1024;