netdev - [PATCH net] net: Fix one possible memleak in ip_setup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 16 Apr 2018 10:16:45 +0800
From:   gfree.wind@....163.com
To:     davem@...emloft.net, kuznet@....inr.ac.ru, netdev@...r.kernel.org
Cc:     Gao Feng <gfree.wind@....163.com>
Subject: [PATCH net] net: Fix one possible memleak in ip_setup_cork

From: Gao Feng <gfree.wind@....163.com>

It would allocate memory in this function when the cork->opt is NULL. But
the memory isn't freed if failed in the latter rt check, and return error
directly. It causes the memleak if its caller is ip_make_skb which also
doesn't free the cork->opt when meet a error.

Now move the rt check ahead to avoid the memleak.

Signed-off-by: Gao Feng <gfree.wind@....163.com>
---
 net/ipv4/ip_output.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 4c11b81..83c73ba 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1109,6 +1109,10 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
 	struct ip_options_rcu *opt;
 	struct rtable *rt;
 
+	rt = *rtp;
+	if (unlikely(!rt))
+		return -EFAULT;
+
 	/*
 	 * setup for corking.
 	 */
@@ -1124,9 +1128,7 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
 		cork->flags |= IPCORK_OPT;
 		cork->addr = ipc->addr;
 	}
-	rt = *rtp;
-	if (unlikely(!rt))
-		return -EFAULT;
+
 	/*
 	 * We steal reference to this route, caller should not release it
 	 */
-- 
1.9.1