linux-kernel - [PATCH 3/3] tap: free skb if flags error

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]

Message-Id: <1512107669-27572-4-git-send-email-wexu@redhat.com>
Date:   Fri,  1 Dec 2017 00:54:29 -0500
From:   wexu@...hat.com
To:     virtualization@...ts.linux-foundation.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Cc:     jasowang@...hat.com, mst@...hat.com, mjrosato@...ux.vnet.ibm.com,
        wexu@...hat.com
Subject: [PATCH 3/3] tap: free skb if flags error

From: Wei Xu <wexu@...hat.com>

tap_recvmsg() supports accepting skb by msg_control after
commit 3b4ba04acca8 ("tap: support receiving skb from msg_control"),
the skb if presented should be freed within the function, otherwise
it would be leaked.

Signed-off-by: Wei Xu <wexu@...hat.com>
Reported-by: Matthew Rosato <mjrosato@...ux.vnet.ibm.com>
---
 drivers/net/tap.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index e9489b8..1c66b75 100644
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -1154,9 +1154,13 @@ static int tap_recvmsg(struct socket *sock, struct msghdr *m,
 		       size_t total_len, int flags)
 {
 	struct tap_queue *q = container_of(sock, struct tap_queue, sock);
+	struct sk_buff *skb = m->msg_control;
 	int ret;
-	if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
+	if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) {
+		if (skb)
+			kfree_skb(skb);
 		return -EINVAL;
+	}
 	ret = tap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT,
 			  m->msg_control);
 	if (ret > total_len) {
-- 
1.8.3.1