From patchwork Thu Dec 13 13:59:28 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [203/241] net: inet_diag -- Return error code if protocol handler is missed Date: Thu, 13 Dec 2012 03:59:28 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 206049 Message-Id: <1355407206-17100-204-git-send-email-herton.krzesinski@canonical.com> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Cyrill Gorcunov , David Miller , Eric Dumazet , Pavel Emelyanov 3.5.7.2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Cyrill Gorcunov commit cacb6ba0f36ab14a507f4ee7697e8332899015d2 upstream. We've observed that in case if UDP diag module is not supported in kernel the netlink returns NLMSG_DONE without notifying a caller that handler is missed. This patch makes __inet_diag_dump to return error code instead. So as example it become possible to detect such situation and handle it gracefully on userspace level. Signed-off-by: Cyrill Gorcunov CC: David Miller CC: Eric Dumazet CC: Pavel Emelyanov Acked-by: Pavel Emelyanov Signed-off-by: David S. Miller Signed-off-by: Herton Ronaldo Krzesinski --- net/ipv4/inet_diag.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 46d1e71..1bfc104 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -875,13 +875,16 @@ static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, struct inet_diag_req_v2 *r, struct nlattr *bc) { const struct inet_diag_handler *handler; + int err = 0; handler = inet_diag_lock_handler(r->sdiag_protocol); if (!IS_ERR(handler)) handler->dump(skb, cb, r, bc); + else + err = PTR_ERR(handler); inet_diag_unlock_handler(handler); - return skb->len; + return err ? : skb->len; } static int inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)