From patchwork Sat Nov 25 20:26:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Siddh Raman Pant X-Patchwork-Id: 13468667 X-Patchwork-Delegate: kuba@kernel.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=siddh.me header.i=code@siddh.me header.b="kfic7x93" 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: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ZohoMailClient: External X-Patchwork-Delegate: kuba@kernel.org 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); } -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); 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; - total_size = size + - dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; + total_size = size + headroom + tailroom + NFC_HEADER_SIZE; skb = 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); 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_llcp_sock *sock, u8 cmd, u16 size) { struct sk_buff *skb; - int err; + int err, headroom, tailroom; if (sock->ssap == 0) return NULL; - skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT, - size + LLCP_HEADER_SIZE, &err); + headroom = sock->dev->tx_headroom; + tailroom = sock->dev->tx_tailroom; + + skb = nfc_alloc_send_skb(&sock->sk, MSG_DONTWAIT, + size + LLCP_HEADER_SIZE, headroom, tailroom, + &err); if (skb == 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 = 0, remaining_len; u8 *msg_ptr, *msg_data; u16 remote_miu; - int err; + int err, headroom, tailroom; pr_debug("Send UI frame len %zd\n", len); @@ -751,6 +755,9 @@ int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap, return -EFAULT; } + headroom = sock->dev->tx_headroom; + tailroom = sock->dev->tx_tailroom; + remaining_len = len; msg_ptr = msg_data; @@ -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); - pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0, - frag_len + LLCP_HEADER_SIZE, &err); + pdu = nfc_alloc_send_skb(&sock->sk, 0, + frag_len + LLCP_HEADER_SIZE, + headroom, tailroom, &err); if (pdu == NULL) { pr_err("Could not allocate PDU (error=%d)\n", err); len -= 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 = sock->sk; struct nfc_dev *dev = nfc_rawsock(sk)->dev; struct sk_buff *skb; - int rc; + int rc, headroom, tailroom; pr_debug("sock=%p sk=%p len=%zu\n", sock, sk, len); @@ -217,7 +217,11 @@ static int rawsock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) if (sock->state != SS_CONNECTED) return -ENOTCONN; - skb = nfc_alloc_send_skb(dev, sk, msg->msg_flags, len, &rc); + headroom = dev->tx_headroom; + tailroom = dev->tx_tailroom; + + skb = nfc_alloc_send_skb(sk, msg->msg_flags, len, headroom, tailroom, + &rc); if (skb == NULL) return rc;