From nobody Wed Dec 17 15:31:50 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7256C4167B for ; Sat, 25 Nov 2023 20:27:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232338AbjKYU1O (ORCPT ); Sat, 25 Nov 2023 15:27:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35742 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229521AbjKYU1F (ORCPT ); Sat, 25 Nov 2023 15:27:05 -0500 Received: from sender-of-o51.zoho.in (sender-of-o51.zoho.in [103.117.158.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8667F127; Sat, 25 Nov 2023 12:27:08 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1700943997; cv=none; d=zohomail.in; s=zohoarc; b=BGfGn3DCDFmOnkDsztjNxOlpWIHIH2sruFlmgC7D8pkdi9qKFpSlaYh+ugi8u8cgDMdWM3KNN0FGXlX57MLnelbQhc9lv40CgfgbssO5FKhZHazb5jeH2W5nmwQXJq/3Vvw4hvPmS0ZWP1lMqfSXfuK8Nk6tTlRuLq/pyN3Lq7c= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.in; s=zohoarc; t=1700943997; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=khXX+6WIAnh+nbfhSLVUt+KViQdJnf6YZ3f3zq0qJyA=; b=Ncih+qyH3NB0WdbOHkljRWMEgbiratVKpxabNsTYoETjMo2gF0Af6WgPwIjA9LotQ3M59jDhH2O4MyeRZ3N0R4iv2B2sKaR/6l5u5txcAs62zCDmLSQkIJUHEk0m490/JR8F5hyJ1dZuBLePXuwSV4spADb3LrCor1iMvvbSijo= ARC-Authentication-Results: i=1; mx.zohomail.in; dkim=pass header.i=siddh.me; spf=pass smtp.mailfrom=code@siddh.me; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1700943997; s=zmail; d=siddh.me; i=code@siddh.me; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:In-Reply-To:References:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=khXX+6WIAnh+nbfhSLVUt+KViQdJnf6YZ3f3zq0qJyA=; b=kfic7x93BI2BMMABAGJ7+jpOVjI7JhUXRyUg1ZCPqgR4fqJisHvm9T5DTztDiHIL QeImSU3M7tV6efOBTccqiEGas8C+0QsaVNUK/etmQl305JMlar9YSipc8NxwYgtC7MH 9LVhKie744FkyWWj+DWy22VBX4w01fmJBjjUQ+Sc= Received: from kampyooter.. (110.226.61.26 [110.226.61.26]) by mx.zoho.in with SMTPS id 1700943994641928.1437515996658; Sun, 26 Nov 2023 01:56:34 +0530 (IST) From: Siddh Raman Pant To: Krzysztof Kozlowski , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/4] nfc: Extract nfc_dev access from nfc_alloc_send_skb() into the callers Date: Sun, 26 Nov 2023 01:56:16 +0530 Message-ID: X-Mailer: git-send-email 2.42.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMailClient: External Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The only reason why nfc_dev was accessed inside nfc_alloc_send_skb() is for getting the headroom and tailroom values. This can cause UAF to be reported from nfc_alloc_send_skb(), but the callers are responsible for managing the device access, and thus the UAF being reported, as the callers (like nfc_llcp_send_ui_frame()) may repeatedly call this function, and this function will repeatedly try to get the same headroom and tailroom values. Thus, put the nfc_dev access responsibility on the callers and accept the headroom and tailroom values directly. Signed-off-by: Siddh Raman Pant --- include/net/nfc/nfc.h | 6 +++--- net/nfc/core.c | 14 +++++++------- net/nfc/llcp_commands.c | 20 ++++++++++++++------ net/nfc/rawsock.c | 8 ++++++-- 4 files changed, 30 insertions(+), 18 deletions(-) diff --git a/include/net/nfc/nfc.h b/include/net/nfc/nfc.h index 5dee575fbe86..efe20a9a8499 100644 --- a/include/net/nfc/nfc.h +++ b/include/net/nfc/nfc.h @@ -260,9 +260,9 @@ static inline const char *nfc_device_name(const struct = nfc_dev *dev) return dev_name(&dev->dev); } =20 -struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk, - unsigned int flags, unsigned int size, - unsigned int *err); +struct sk_buff *nfc_alloc_send_skb(struct sock *sk, unsigned int flags, + unsigned int size, int headroom, + int tailroom, unsigned int *err); struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp); =20 int nfc_set_remote_general_bytes(struct nfc_dev *dev, diff --git a/net/nfc/core.c b/net/nfc/core.c index eb2c0959e5b6..1f7d20971f6f 100644 --- a/net/nfc/core.c +++ b/net/nfc/core.c @@ -705,25 +705,25 @@ EXPORT_SYMBOL(nfc_tm_deactivated); /** * nfc_alloc_send_skb - allocate a skb for data exchange responses * - * @dev: device sending the response * @sk: socket sending the response * @flags: MSG_DONTWAIT flag * @size: size to allocate + * @headroom: Extra headroom, in addition to size + * @tailroom: Extra tailroom, in addition to size * @err: pointer to memory to store the error code */ -struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk, - unsigned int flags, unsigned int size, - unsigned int *err) +struct sk_buff *nfc_alloc_send_skb(struct sock *sk, unsigned int flags, + unsigned int size, int headroom, + int tailroom, unsigned int *err) { struct sk_buff *skb; unsigned int total_size; =20 - total_size =3D size + - dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; + total_size =3D size + headroom + tailroom + NFC_HEADER_SIZE; =20 skb =3D sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err); if (skb) - skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); + skb_reserve(skb, headroom + NFC_HEADER_SIZE); =20 return skb; } diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c index e2680a3bef79..39c7c59bbf66 100644 --- a/net/nfc/llcp_commands.c +++ b/net/nfc/llcp_commands.c @@ -314,13 +314,17 @@ static struct sk_buff *llcp_allocate_pdu(struct nfc_l= lcp_sock *sock, u8 cmd, u16 size) { struct sk_buff *skb; - int err; + int err, headroom, tailroom; =20 if (sock->ssap =3D=3D 0) return NULL; =20 - skb =3D nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT, - size + LLCP_HEADER_SIZE, &err); + headroom =3D sock->dev->tx_headroom; + tailroom =3D sock->dev->tx_tailroom; + + skb =3D nfc_alloc_send_skb(&sock->sk, MSG_DONTWAIT, + size + LLCP_HEADER_SIZE, headroom, tailroom, + &err); if (skb =3D=3D NULL) { pr_err("Could not allocate PDU\n"); return NULL; @@ -734,7 +738,7 @@ int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, = u8 ssap, u8 dsap, size_t frag_len =3D 0, remaining_len; u8 *msg_ptr, *msg_data; u16 remote_miu; - int err; + int err, headroom, tailroom; =20 pr_debug("Send UI frame len %zd\n", len); =20 @@ -751,6 +755,9 @@ int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, = u8 ssap, u8 dsap, return -EFAULT; } =20 + headroom =3D sock->dev->tx_headroom; + tailroom =3D sock->dev->tx_tailroom; + remaining_len =3D len; msg_ptr =3D msg_data; =20 @@ -763,8 +770,9 @@ int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, = u8 ssap, u8 dsap, pr_debug("Fragment %zd bytes remaining %zd", frag_len, remaining_len); =20 - pdu =3D nfc_alloc_send_skb(sock->dev, &sock->sk, 0, - frag_len + LLCP_HEADER_SIZE, &err); + pdu =3D nfc_alloc_send_skb(&sock->sk, 0, + frag_len + LLCP_HEADER_SIZE, + headroom, tailroom, &err); if (pdu =3D=3D NULL) { pr_err("Could not allocate PDU (error=3D%d)\n", err); len -=3D remaining_len; diff --git a/net/nfc/rawsock.c b/net/nfc/rawsock.c index 5125392bb68e..fab1facb7105 100644 --- a/net/nfc/rawsock.c +++ b/net/nfc/rawsock.c @@ -207,7 +207,7 @@ static int rawsock_sendmsg(struct socket *sock, struct = msghdr *msg, size_t len) struct sock *sk =3D sock->sk; struct nfc_dev *dev =3D nfc_rawsock(sk)->dev; struct sk_buff *skb; - int rc; + int rc, headroom, tailroom; =20 pr_debug("sock=3D%p sk=3D%p len=3D%zu\n", sock, sk, len); =20 @@ -217,7 +217,11 @@ static int rawsock_sendmsg(struct socket *sock, struct= msghdr *msg, size_t len) if (sock->state !=3D SS_CONNECTED) return -ENOTCONN; =20 - skb =3D nfc_alloc_send_skb(dev, sk, msg->msg_flags, len, &rc); + headroom =3D dev->tx_headroom; + tailroom =3D dev->tx_tailroom; + + skb =3D nfc_alloc_send_skb(sk, msg->msg_flags, len, headroom, tailroom, + &rc); if (skb =3D=3D NULL) return rc; =20 --=20 2.42.0