From patchwork Mon Nov 22 11:34:49 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Eckelmann X-Patchwork-Id: 596 Return-Path: Received: from mail.gmx.net (mailout-de.gmx.net [213.165.64.22]) by open-mesh.org (Postfix) with SMTP id 6C6671545A8 for ; Mon, 22 Nov 2010 12:35:28 +0100 (CET) Received: (qmail invoked by alias); 22 Nov 2010 11:35:27 -0000 Received: from camo157-92.hrz.tu-chemnitz.de (EHLO localhost) [134.109.157.92] by mail.gmx.net (mp068) with SMTP; 22 Nov 2010 12:35:27 +0100 X-Authenticated: #15668376 X-Provags-ID: V01U2FsdGVkX19+Ft9Qqt5+XrPLxcHLv/xFlNctxnFLLyecMH5v6R 8pZRaDieuyLanW From: Sven Eckelmann To: greg@kroah.com Date: Mon, 22 Nov 2010 12:34:49 +0100 Message-Id: <1290425690-5119-3-git-send-email-sven.eckelmann@gmx.de> X-Mailer: git-send-email 1.7.2.3 In-Reply-To: <201011221129.06220.sven.eckelmann@gmx.de> References: <201011221129.06220.sven.eckelmann@gmx.de> X-Y-GMX-Trusted: 0 Cc: b.a.t.m.a.n@lists.open-mesh.org, Marek Lindner Subject: [B.A.T.M.A.N.] [PATCH 1/2] Staging: batman-adv: ensure that eth_type_trans gets linear memory X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 2.1.11 Precedence: list Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Nov 2010 11:35:28 -0000 From: Marek Lindner eth_type_trans tries to pull data with the length of the ethernet header from the skb. We only ensured that enough data for the first ethernet header and the batman header is available in non-paged memory of the skb and not for the ethernet after the batman header. eth_type_trans would fail sometimes with drivers which don't ensure that all there data is perfectly linearised. The failure was noticed through a kernel bug Oops generated by the skb_pull inside eth_type_trans. Reported-by: Rafal Lesniak Signed-off-by: Marek Lindner Signed-off-by: Sven Eckelmann --- The same patch was also submitted for 2.6.38 and it is also possible to merge that patch in 2.6.37 and then merge 2.6.37 in 2.6.28 drivers/staging/batman-adv/soft-interface.c | 14 ++++++++++---- 1 files changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/staging/batman-adv/soft-interface.c b/drivers/staging/batman-adv/soft-interface.c index 3904db9..0e99618 100644 --- a/drivers/staging/batman-adv/soft-interface.c +++ b/drivers/staging/batman-adv/soft-interface.c @@ -194,14 +194,15 @@ void interface_rx(struct net_device *soft_iface, struct bat_priv *priv = netdev_priv(soft_iface); /* check if enough space is available for pulling, and pull */ - if (!pskb_may_pull(skb, hdr_size)) { - kfree_skb(skb); - return; - } + if (!pskb_may_pull(skb, hdr_size)) + goto dropped; + skb_pull_rcsum(skb, hdr_size); /* skb_set_mac_header(skb, -sizeof(struct ethhdr));*/ /* skb->dev & skb->pkt_type are set here */ + if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) + goto dropped; skb->protocol = eth_type_trans(skb, soft_iface); /* should not be neccesary anymore as we use skb_pull_rcsum() @@ -216,6 +217,11 @@ void interface_rx(struct net_device *soft_iface, soft_iface->last_rx = jiffies; netif_rx(skb); + return; + +dropped: + kfree_skb(skb); + return; } #ifdef HAVE_NET_DEVICE_OPS