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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, T_DKIMWL_WL_HIGH,USER_AGENT_MUTT 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 DC8FBC43219 for ; Sat, 4 May 2019 09:52:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A513B2084A for ; Sat, 4 May 2019 09:52:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556963544; bh=BqZ5JiWkvHkc3lAZvNDNmOQq2YEoCS6tHKgUvGvJXVQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=hSp3qACAGRZTRtemZi/+3GGHtPy+wVNjmcoTH7SocoEp9GBOdDnWVfkJU4DPg0q/U FA2GVEUGsEmHsnJNMfMaQa4xgiYGq/vnKeEYO6Fh7OkjqOXO5MjiN3pdlBmHdGrcDJ vRLD3fxVvFS9wzKTJcTI9u2fgLVhKHZN7+4OuVQY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726693AbfEDJwX (ORCPT ); Sat, 4 May 2019 05:52:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:54842 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725823AbfEDJwX (ORCPT ); Sat, 4 May 2019 05:52:23 -0400 Received: from localhost.localdomain (unknown [151.66.59.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4EE44206DF; Sat, 4 May 2019 09:52:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556963542; bh=BqZ5JiWkvHkc3lAZvNDNmOQq2YEoCS6tHKgUvGvJXVQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pxvM9teiIZbYOqhRHkz2n/HXkEHEr4dOOGdVnkTliw4EMLPRagrs4iAh++HUHlOpK cJk4GPEwdkgtD0S8XWXjlNjpZb7jAGSUbczUa/Gk/aXYSN67UibOXq97ultTeAQt7o /cawM5/Np/2FRGObAEQAXhNgHi2W3t7xdTjaQURY= Date: Sat, 4 May 2019 11:52:16 +0200 From: Lorenzo Bianconi To: Dan Carpenter Cc: Felix Fietkau , Ryder Lee , Lorenzo Bianconi , Roy Luo , Kalle Valo , Matthias Brugger , linux-wireless@vger.kernel.org, linux-mediatek@lists.infradead.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] mt76: mt7615: Use after free in mt7615_mcu_set_bcn() Message-ID: <20190504095215.GA23263@localhost.localdomain> References: <20190503130909.GI29695@mwanda> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="PNTmBPCT7hxwcZjr" Content-Disposition: inline In-Reply-To: <20190503130909.GI29695@mwanda> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org --PNTmBPCT7hxwcZjr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Acked-by: Lorenzo Bianconi > We dereference "skb" when we assign: >=20 > req.pkt_len =3D cpu_to_le16(MT_TXD_SIZE + skb->len); > ^^^^^^^^ > So this patch just moves the dev_kfree_skb() down a bit to avoid the > use after free. >=20 > Fixes: 04b8e65922f6 ("mt76: add mac80211 driver for MT7615 PCIe-based chi= psets") > Signed-off-by: Dan Carpenter > --- > drivers/net/wireless/mediatek/mt76/mt7615/mcu.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >=20 > diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c b/drivers/ne= t/wireless/mediatek/mt76/mt7615/mcu.c > index ea67c6022fe6..dc1301effa24 100644 > --- a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c > +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c > @@ -1270,7 +1270,6 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, stru= ct ieee80211_vif *vif, > mt7615_mac_write_txwi(dev, (__le32 *)(req.pkt), skb, wcid, NULL, > 0, NULL); > memcpy(req.pkt + MT_TXD_SIZE, skb->data, skb->len); > - dev_kfree_skb(skb); > =20 > req.omac_idx =3D mvif->omac_idx; > req.enable =3D en; > @@ -1281,6 +1280,7 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, stru= ct ieee80211_vif *vif, > req.pkt_len =3D cpu_to_le16(MT_TXD_SIZE + skb->len); > req.tim_ie_pos =3D cpu_to_le16(MT_TXD_SIZE + tim_off); > =20 > + dev_kfree_skb(skb); > skb =3D mt7615_mcu_msg_alloc(&req, sizeof(req)); > =20 > return mt7615_mcu_msg_send(dev, skb, MCU_EXT_CMD_BCN_OFFLOAD, > --=20 > 2.18.0 >=20 --PNTmBPCT7hxwcZjr Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCXM1gzAAKCRA6cBh0uS2t rDeKAQDGjECddgKPoW1n3Dnye8aHew95bCQqgsIeRCLiVSH00QD/VWP4FLjdbVHM +9OT95BeBDbj0eG7VaB6OROPr+8wLwg= =UKNW -----END PGP SIGNATURE----- --PNTmBPCT7hxwcZjr--