linux-kernel - [PATCH 3.16 220/346] qdisc: fix a module refcount leak in qdisc_create

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: <lsq.1479082460.712551175@decadent.org.uk>
Date:   Mon, 14 Nov 2016 00:14:20 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org,
        "John Fastabend" <john.r.fastabend@...el.com>,
        "Eric Dumazet" <edumazet@...gle.com>,
        "David S. Miller" <davem@...emloft.net>
Subject: [PATCH 3.16 220/346] qdisc: fix a module refcount leak in
 qdisc_create_dflt()

3.16.39-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@...gle.com>

commit 166ee5b87866de07a3e56c1b757f2b5cabba72a5 upstream.

Should qdisc_alloc() fail, we must release the module refcount
we got right before.

Fixes: 6da7c8fcbcbd ("qdisc: allow setting default queuing discipline")
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Acked-by: John Fastabend <john.r.fastabend@...el.com>
Acked-by: John Fastabend <john.r.fastabend@...el.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 net/sched/sch_generic.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -590,18 +590,19 @@ struct Qdisc *qdisc_create_dflt(struct n
 	struct Qdisc *sch;
 
 	if (!try_module_get(ops->owner))
-		goto errout;
+		return NULL;
 
 	sch = qdisc_alloc(dev_queue, ops);
-	if (IS_ERR(sch))
-		goto errout;
+	if (IS_ERR(sch)) {
+		module_put(ops->owner);
+		return NULL;
+	}
 	sch->parent = parentid;
 
 	if (!ops->init || ops->init(sch, NULL) == 0)
 		return sch;
 
 	qdisc_destroy(sch);
-errout:
 	return NULL;
 }
 EXPORT_SYMBOL(qdisc_create_dflt);