From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52BE5C433E0 for ; Wed, 27 May 2020 18:08:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 385F32075A for ; Wed, 27 May 2020 18:08:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Ph9JeVX/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391876AbgE0SIP (ORCPT ); Wed, 27 May 2020 14:08:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391703AbgE0SIO (ORCPT ); Wed, 27 May 2020 14:08:14 -0400 Received: from mail-yb1-xb42.google.com (mail-yb1-xb42.google.com [IPv6:2607:f8b0:4864:20::b42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48ABFC03E97D for ; Wed, 27 May 2020 11:08:14 -0700 (PDT) Received: by mail-yb1-xb42.google.com with SMTP id g39so6256102ybe.7 for ; Wed, 27 May 2020 11:08:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=az36+VEEhMF1p2T3V/nE9Cjv2UZTzI3VDCbfw5ZKcrs=; b=Ph9JeVX/lmymsfJ+4K+9KGQT5Hsvp38tXB5poOgNqo+LUqsXHEOuIHDu+gIe39L0Nw 3KgoCKEOpDYjNUpc0XpbkYPVopBAWSjr/ha7biuQjMTGuzJIwC9z5xwqbs44SLFpRL8Q E/vEE5VCahSbPx1dmU2PmT3Sq5z+vq+0nVRZfa0AV1I5ojYk/DxEiU/uA1XgNUM3GhTh MvHtW6UfNt4DRqwVRHmCyD8PtVD+1XEOMbyxR5W6AGhIyVcMkEAkOdHRWscpd1asY9r3 GApMzsEebogxDMSaBaMQtfjg8b1hyCX2UVQbF+Ew1J87v50XB+mtw1mt/dfTSzRqkPKp PrVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=az36+VEEhMF1p2T3V/nE9Cjv2UZTzI3VDCbfw5ZKcrs=; b=s1kfXXS/38rBhRkv6htx0le72xylGUlswusXh0egI8+32gHc+WpCXNI2coUmq4Zbj3 iLD7ew1Uw94c9TfTFrVl7Mpedd1pBUrQqc6RZccb3QBwZuc7him3W2YBXgWkl+hX4g2C 9BFN1p2SuA/GhyyeCoR7x34NHsLuhIJ6cd2EAD64TLV2qV62frkAxCuLY21uiYgb04V/ r1V66uF/I+JjWjTaonohINWupxDSgexY++VHJ5WipnHa54HKjq0DH8rEYdG0cn6XKm7X TTXBHDYdS3UUwWCXvCekkvnDCmViMYq3VU0VWsnezfBiViQZeEz8V+g5vPSs5ZKQzCo2 mL4Q== X-Gm-Message-State: AOAM530IF3Hkej0MYKXfc0QX4TUVCDsrwQatF2Y267GN+1tzF+cNUeMq MNTXzWaKewd9xeFBM/jgXoI+XT+i2ctbBFsVf4tzWA== X-Google-Smtp-Source: ABdhPJyyLDPIM2dDHHdeQAkyW76kdq3a56XkIwI2yvc306DcUkhgpSuLD+LPwea4492FvcdUTW2vjV1ODB+hY93WKVQ= X-Received: by 2002:a25:2504:: with SMTP id l4mr13133395ybl.408.1590602893213; Wed, 27 May 2020 11:08:13 -0700 (PDT) MIME-Version: 1.0 References: <20200527175808.peynuk7a6webysv3@kili.mountain> In-Reply-To: <20200527175808.peynuk7a6webysv3@kili.mountain> From: Eric Dumazet Date: Wed, 27 May 2020 11:08:01 -0700 Message-ID: Subject: Re: [PATCH v2] airo: Fix read overflows sending packets To: Dan Carpenter Cc: Kalle Valo , Hu Jiahui , Security Officers , linux-wireless@vger.kernel.org, Jakub Kicinski Content-Type: text/plain; charset="UTF-8" Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Wed, May 27, 2020 at 10:58 AM Dan Carpenter wrote: > > The problem is that we always copy a minimum of ETH_ZLEN (60) bytes from > skb->data even when skb->len is less than ETH_ZLEN so it leads to a read > overflow. > > The fix is to pad skb->data with zeroes so that it's never less than > ETH_ZLEN bytes. > > Cc: > Reported-by: Hu Jiahui > Signed-off-by: Dan Carpenter > --- > v2: remove an unnecessary if statement > increment the ->tx_dropped count on failure > fix found two more instances of the same bug. > fix typo in the "Cc: " tag > > drivers/net/wireless/cisco/airo.c | 26 ++++++++++++++++---------- > 1 file changed, 16 insertions(+), 10 deletions(-) > > diff --git a/drivers/net/wireless/cisco/airo.c b/drivers/net/wireless/cisco/airo.c > index 8363f91df7ea..c80712e61ccf 100644 > --- a/drivers/net/wireless/cisco/airo.c > +++ b/drivers/net/wireless/cisco/airo.c > @@ -1925,6 +1925,11 @@ static netdev_tx_t mpi_start_xmit(struct sk_buff *skb, > airo_print_err(dev->name, "%s: skb == NULL!",__func__); > return NETDEV_TX_OK; > } > + if (skb_padto(skb, ETH_ZLEN)) { > + dev->stats.tx_dropped++; > + return NETDEV_TX_OK; > + } > + > npacks = skb_queue_len (&ai->txq); > > if (npacks >= MAXTXQ - 1) { > @@ -1975,8 +1980,7 @@ static int mpi_send_packet (struct net_device *dev) > return 0; > } > > - /* check min length*/ > - len = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN; Note that skb_padto() does not change skb->len So this patch could trigger a hardware bug. > + len = skb->len; > buffer = skb->data; > > ai->txfids[0].tx_desc.offset = 0; > @@ -2118,7 +2122,6 @@ static void airo_end_xmit(struct net_device *dev) { > static netdev_tx_t airo_start_xmit(struct sk_buff *skb, > struct net_device *dev) > { > - s16 len; > int i, j; > struct airo_info *priv = dev->ml_priv; > u32 *fids = priv->fids; > @@ -2127,6 +2130,10 @@ static netdev_tx_t airo_start_xmit(struct sk_buff *skb, > airo_print_err(dev->name, "%s: skb == NULL!", __func__); > return NETDEV_TX_OK; > } > + if (skb_padto(skb, ETH_ZLEN)) { > + dev->stats.tx_dropped++; > + return NETDEV_TX_OK; > + } > > /* Find a vacant FID */ > for( i = 0; i < MAX_FIDS / 2 && (fids[i] & 0xffff0000); i++ ); > @@ -2140,10 +2147,8 @@ static netdev_tx_t airo_start_xmit(struct sk_buff *skb, > return NETDEV_TX_BUSY; > } > } > - /* check min length*/ > - len = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN; > /* Mark fid as used & save length for later */ > - fids[i] |= (len << 16); > + fids[i] |= (skb->len << 16); > priv->xmit.skb = skb; > priv->xmit.fid = i; > if (down_trylock(&priv->sem) != 0) { > @@ -2185,7 +2190,6 @@ static void airo_end_xmit11(struct net_device *dev) { > static netdev_tx_t airo_start_xmit11(struct sk_buff *skb, > struct net_device *dev) > { > - s16 len; > int i, j; > struct airo_info *priv = dev->ml_priv; > u32 *fids = priv->fids; > @@ -2201,6 +2205,10 @@ static netdev_tx_t airo_start_xmit11(struct sk_buff *skb, > airo_print_err(dev->name, "%s: skb == NULL!", __func__); > return NETDEV_TX_OK; > } > + if (skb_padto(skb, ETH_ZLEN)) { > + dev->stats.tx_dropped++; > + return NETDEV_TX_OK; > + } > > /* Find a vacant FID */ > for( i = MAX_FIDS / 2; i < MAX_FIDS && (fids[i] & 0xffff0000); i++ ); > @@ -2214,10 +2222,8 @@ static netdev_tx_t airo_start_xmit11(struct sk_buff *skb, > return NETDEV_TX_BUSY; > } > } > - /* check min length*/ > - len = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN; > /* Mark fid as used & save length for later */ > - fids[i] |= (len << 16); > + fids[i] |= (skb->len << 16); > priv->xmit11.skb = skb; > priv->xmit11.fid = i; > if (down_trylock(&priv->sem) != 0) { > -- > 2.11.0 >