[PATCH 3.14 34/59] connector: bump skb->users before callback invocation

Greg Kroah-Hartman
2016-01-27T20:08:11Z

From: Florian Westphal <fw@strlen.de>

[ Upstream commit 55285bf09427c5abf43ee1d54e892f352092b1f1 ]

Dmitry reports memleak with syskaller program.
Problem is that connector bumps skb usecount but might not invoke callback.

So move skb_get to where we invoke the callback.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/connector/connector.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

--- a/drivers/connector/connector.c
+++ b/drivers/connector/connector.c
@@ -154,26 +154,21 @@ static int cn_call_callback(struct sk_bu
*
* It checks skb, netlink header and msg sizes, and calls callback helper.
*/
-static void cn_rx_skb(struct sk_buff *__skb)
+static void cn_rx_skb(struct sk_buff *skb)
{
struct nlmsghdr *nlh;
- struct sk_buff *skb;
int len, err;

- skb = skb_get(__skb);
-
if (skb->len >= NLMSG_HDRLEN) {
nlh = nlmsg_hdr(skb);
len = nlmsg_len(nlh);

if (len < (int)sizeof(struct cn_msg) ||
skb->len < nlh->nlmsg_len ||
- len > CONNECTOR_MAX_MSG_SIZE) {
- kfree_skb(skb);
+ len > CONNECTOR_MAX_MSG_SIZE)
return;
- }

- err = cn_call_callback(skb);
+ err = cn_call_callback(skb_get(skb));
if (err < 0)
kfree_skb(skb);
}