From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.remote-ip=81.169.146.163 ARC-Seal: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=fail; t=1794333470; b=ePSiT9GA2VEBNEhiVYh3cVh7GGZW/bIiCJPMRnCXDhAxHQbnx1d/KY1ZCmFpQ0Egc02/ fnetPDR1Z1GeFFJRrECCs8U6/9tArz8MZ0V4gBWFbkyEXGtbt0s49rTgiPwJm3ytcZnAq Oj0tvuqOHz57v1AX0SwDgLITu/TgfjuPv/EEE04XsjJXKDkAQLuIUO85kFM1dskCd6Yfo SfPhcskREttcW1Jy9XUA++LD+2I6h+SIlZFf0ZJLbTk74PF23C9G6Nw7/sqG5GW3stoCY uIkCYC9xfrQTOhE5lFRKO/V1S6BxqACvt2I++Fcos8uwg2e28tWBnz+jkZpNMWPfiWA== ARC-Message-Signature: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794333470; h=DMARC-Filter:X-RZG-CLASS-ID:DKIM-Signature:DKIM-Signature:X-RZG-AUTH: Received:From:To:Cc:Subject:Date:Message-ID:X-Mailer:In-Reply-To: References:MIME-Version:Content-Transfer-Encoding:Content-Type; bh=u/y5BOgYw8S2/ncwOjF/uSlfrUE9POplcq9NJ+UkR/E=; b=aiCLqoYriDkc7BBMWIXCVkgiDFbZa3DT82VNN600WlAwtbgMeNMe3DpouaEgx+2Yri6S kBYaCNz4GveP2pv5+kXdHH2BM4Hgu+EzXtBahrIQD6hBB31Rkt1vWkBx6mjIXKQpQe1Dj rLxr2Vgy+68yGVGxT8vXihmNgmtLVYrn/+2F0tdurx9NxO+YCmKXxswXenzx3wzbf6fZ/ xoa7puUrh7NgJroEDYznosnLflYIdovVdpvA293H5rzEFpISqqubMp5o+j78eqbOuTa/1 UeN6BXo8hPfPjQZw3QMR94CFfDlKcwwsn1v8muTiVzh5FTEwrytyqi9y3irVC2uZsUQ== ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass header.from=hartkopp.net; spf=fail smtp.mailfrom=hartkopp.net; dkim=pass header.d=hartkopp.net header.i=@hartkopp.net header.a=rsa-sha256 header.s=strato-dkim-0002 header.b=LLJOj2qN; dkim=pass header.d=hartkopp.net header.i=@hartkopp.net header.a=ed25519-sha256 header.s=strato-dkim-0003 header.b=3xO5GHXE; arc=fail smtp.remote-ip=81.169.146.163 Received: from mo4-p00-ob.smtp.rzone.de (mo4-p00-ob.smtp.rzone.de [81.169.146.163]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C4800606A202 for ; Tue, 10 Nov 2026 17:57:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org C4800606A202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=hartkopp.net Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=hartkopp.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=hartkopp.net header.i=@hartkopp.net header.a=rsa-sha256 header.s=strato-dkim-0002 header.b=LLJOj2qN; dkim=pass header.d=hartkopp.net header.i=@hartkopp.net header.a=ed25519-sha256 header.s=strato-dkim-0003 header.b=3xO5GHXE ARC-Seal: i=1; a=rsa-sha256; t=1794333446; cv=none; d=strato.com; s=strato-dkim-0002; b=ahblBdlFtyFva/cLerizE61t7obXx79IKbVg7VPjfjS91hTzz70iDL5lFJNUkXhIDY zSRez/hmzSwqT/tTE11Dt9Y1kOu2G9gcKSRPJfVWGepBuZlAbNusIRpNRj3VLYMe/4pU Pq3IPbvNHE67aNsV+Izqn986sDyJo5FUPAXNHi9PBCmTUnKb4vrpXBvLyTafa4+jNLXd WC5XpLFG0N2ce9iq/qBKzXTyBinar0tuhEeOrXkz2AcxOcQSZYoCqdOmi0nls3aW42Yf ll8xSzFdRIyyYdEkbcfAwx/euAbEGsyFJnWX+TlK9nQ11AXXIDGAzQn3mUD9YajYFfOn qGvw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; t=1794333446; s=strato-dkim-0002; d=strato.com; h=References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Cc:Date: From:Subject:Sender; bh=u/y5BOgYw8S2/ncwOjF/uSlfrUE9POplcq9NJ+UkR/E=; b=n14pwqA9vIvFeCWLx59FflQ+I2rVZ3W2I/q/8o/lUsUBPEyRbLivBGf1tCzPqsVCsg wIPVGlz+4Mo9CWMd8uOn1s79VAUabwhZQq84lu4zWQrUx/uyRXZMsR5g6jEtKsG2W1g4 KUd98TgsR04bcT8qZfnIKcdKj5kwDnGe79QOueUUPVFDEj9GEQQ26VaNV8n72v0IR0NT TWVvGHHWknL5ivB+XC1ctyW6P73IuUBdaLcv95p1MVbs830uJvj6qd2GlzqjbJu1FyDE qV1owz/X6WHsdzf32YievH3Zu3MsutXerdwbUnYWNdBYc106q7aQ37GggE2X4eV5NDQ/ UqWw== ARC-Authentication-Results: i=1; strato.com; arc=none; dkim=none X-RZG-CLASS-ID: mo00 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1794333446; s=strato-dkim-0002; d=hartkopp.net; h=References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Cc:Date: From:Subject:Sender; bh=u/y5BOgYw8S2/ncwOjF/uSlfrUE9POplcq9NJ+UkR/E=; b=LLJOj2qNuAQ1sTBvC5J27kGaWTsaVHQ1Sp5UkEA1xVSIrtKvJAD8lHH4ciumk1ODEv JLZGYfPkRZu+sCaJVMH7FxpH1cQyl1GtP8+0+Xe/g9lCirOLdZddJZDMtY5Fyiu6h8us uLSAsVaKtg/17R8a5hWreJ/j+k0G+ghe/TjSf1F0I8pe/Sq2zok52uhw7eSozSP7gJvq e94biFRbwtW6q1kYoG39vqSKmE694y7I7P6rTUPgY5kJGQztPu4wAwGZktlWWmVFoBee CFbK4IfKWF8+wTwkpz7CCsgVBCsjnyx63hk7qdDq6PoZes4P8KlEmSwgQ1D3DauU0ejk oFeQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; t=1794333446; s=strato-dkim-0003; d=hartkopp.net; h=References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Cc:Date: From:Subject:Sender; bh=u/y5BOgYw8S2/ncwOjF/uSlfrUE9POplcq9NJ+UkR/E=; b=3xO5GHXEP41GtBMY6TSfnN+5HoEVc/c3OqWrJaNnYegC+WYYolcqk9UevfEYB405tC gui1NRzN9xnE4J1FURDA== X-RZG-AUTH: ":P2MHfkW8eP4Mre39l357AZT/I7AY/7nT2yrDxb8mjH4JKvMdQv2tTUsMrZpkO3Mw3lZ/t54cFxeEQ7s8bDup0Q==" Received: from vivo.lan by smtp.strato.de (RZmta 55.6.3 AUTH) with ESMTPSA id Kfdf2a2AAHvQ1cI (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Tue, 10 Nov 2026 18:57:26 +0100 (CET) From: Oliver Hartkopp To: stable@vger.kernel.org Cc: Sasha Levin , Marc Kleine-Budde , Oliver Hartkopp Subject: [PATCH 6.18.y] can: replace ARPHRD_CAN type checks with can_get_ml_priv() Date: Tue, 10 Nov 2026 18:57:14 +0100 Message-ID: <20261110175714.791740-1-socketcan@hartkopp.net> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261109200450-failed-6.18-962947b69589@kernel.org> References: <20261109200450-failed-6.18-962947b69589@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="us-ascii" commit 962947b69589881167054bae5accc8abfd5aa4b6 upstream. Commit 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device") introduced an explicit way to assign the midlayer private pointer (dev->ml_priv) to named users like ML_PRIV_CAN. A valid pointer returned by can_get_ml_priv() therefore identifies a real CAN device. The referenced commit only converted the j1939 and proc code to this check, while the other parts of the CAN subsystem still rely on dev->type == ARPHRD_CAN. The TUNSETLINK ioctl allows a down TUN/TAP device to set its hardware type to ARPHRD_CAN while dev->ml_priv remains NULL. Such a repurposed netdevice passes the ARPHRD_CAN checks. Commit 8aa59e355949 ("can: af_can: fix NULL pointer dereference in can_rx_register()") already made can_rx_register() reject such devices. But can_rx_unregister() still only checks dev->type and dereferences the NULL ml_priv when it walks the receive lists of the device. CAN_ISOTP reaches this path: isotp_bind() ignores the return values of can_rx_register() and binds the socket anyway. When the socket is released or the device is unregistered, isotp_release() and isotp_notify() remove the filters that have never been registered and trigger the NULL pointer dereference in can_rx_unregister(). This only requires owning a TUN/TAP device or CAP_NET_ADMIN in an unprivileged user namespace. Convert the remaining ARPHRD_CAN checks in af_can, bcm, gw, isotp and raw to can_get_ml_priv(). Fixes: 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device") Cc: stable@vger.kernel.org Cc: Oleksij Rempel Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20261027-can-rx-lock-v12-1-eb5afc2d8b9b@hartkopp.net Signed-off-by: Marc Kleine-Budde [ backport to 6.18: This tree has no can_skb_ext, so only the ARPHRD_CAN check is removed from the conditions in can_rcv(), canfd_rcv() and canxl_rcv(). Add the include to raw.c, which upstream got with commit faba5860fcf9 ("can: raw: instantly reject disabled CAN frames"). ] Signed-off-by: Oliver Hartkopp --- net/can/af_can.c | 12 ++++++------ net/can/bcm.c | 7 ++++--- net/can/gw.c | 7 ++++--- net/can/isotp.c | 5 +++-- net/can/raw.c | 5 +++-- 5 files changed, 20 insertions(+), 16 deletions(-) diff --git a/net/can/af_can.c b/net/can/af_can.c index 52d72d56f2dd..539e9ba06ccc 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -226,7 +226,7 @@ int can_send(struct sk_buff *skb, int loop) goto inval_skb; } - if (unlikely(skb->dev->type != ARPHRD_CAN)) { + if (unlikely(!can_get_ml_priv(skb->dev))) { err = -EPERM; goto inval_skb; } @@ -452,7 +452,7 @@ int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id, /* insert new receiver (dev,canid,mask) -> (func,data) */ - if (dev && (dev->type != ARPHRD_CAN || !can_get_ml_priv(dev))) + if (dev && !can_get_ml_priv(dev)) return -ENODEV; if (dev && !net_eq(net, dev_net(dev))) @@ -519,7 +519,7 @@ void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id, struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats; struct can_dev_rcv_lists *dev_rcv_lists; - if (dev && dev->type != ARPHRD_CAN) + if (dev && !can_get_ml_priv(dev)) return; if (dev && !net_eq(net, dev_net(dev))) @@ -685,7 +685,7 @@ static void can_receive(struct sk_buff *skb, struct net_device *dev) static int can_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { - if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || !can_is_can_skb(skb))) { + if (unlikely(!can_get_ml_priv(dev) || !can_is_can_skb(skb))) { pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n", dev->type, skb->len); @@ -700,7 +700,7 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev, static int canfd_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { - if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || !can_is_canfd_skb(skb))) { + if (unlikely(!can_get_ml_priv(dev) || !can_is_canfd_skb(skb))) { pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n", dev->type, skb->len); @@ -715,7 +715,7 @@ static int canfd_rcv(struct sk_buff *skb, struct net_device *dev, static int canxl_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { - if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || !can_is_canxl_skb(skb))) { + if (unlikely(!can_get_ml_priv(dev) || !can_is_canxl_skb(skb))) { pr_warn_once("PF_CAN: dropped non conform CAN XL skbuff: dev type %d, len %d\n", dev->type, skb->len); diff --git a/net/can/bcm.c b/net/can/bcm.c index 6d67af0a3b14..5f3321ede520 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -54,6 +54,7 @@ #include #include #include +#include #include #include #include @@ -1706,7 +1707,7 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) goto out_release; } - if (dev->type != ARPHRD_CAN) { + if (!can_get_ml_priv(dev)) { dev_put(dev); ret = -ENODEV; goto out_release; @@ -1854,7 +1855,7 @@ static int bcm_notifier(struct notifier_block *nb, unsigned long msg, { struct net_device *dev = netdev_notifier_info_to_dev(ptr); - if (dev->type != ARPHRD_CAN) + if (!can_get_ml_priv(dev)) return NOTIFY_DONE; if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN) return NOTIFY_DONE; @@ -2011,7 +2012,7 @@ static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, ret = -ENODEV; goto fail; } - if (dev->type != ARPHRD_CAN) { + if (!can_get_ml_priv(dev)) { dev_put(dev); ret = -ENODEV; goto fail; diff --git a/net/can/gw.c b/net/can/gw.c index 79fa58cb232e..de222fa93d6c 100644 --- a/net/can/gw.c +++ b/net/can/gw.c @@ -52,6 +52,7 @@ #include #include #include +#include #include #include #include @@ -603,7 +604,7 @@ static int cgw_notifier(struct notifier_block *nb, struct net_device *dev = netdev_notifier_info_to_dev(ptr); struct net *net = dev_net(dev); - if (dev->type != ARPHRD_CAN) + if (!can_get_ml_priv(dev)) return NOTIFY_DONE; if (msg == NETDEV_UNREGISTER) { @@ -1154,7 +1155,7 @@ static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh, if (!gwj->src.dev) goto out; - if (gwj->src.dev->type != ARPHRD_CAN) + if (!can_get_ml_priv(gwj->src.dev)) goto out; gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx); @@ -1162,7 +1163,7 @@ static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh, if (!gwj->dst.dev) goto out; - if (gwj->dst.dev->type != ARPHRD_CAN) + if (!can_get_ml_priv(gwj->dst.dev)) goto out; /* is sending the skb back to the incoming interface intended? */ diff --git a/net/can/isotp.c b/net/can/isotp.c index e3261fb4663a..dfe3fd47e220 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -65,6 +65,7 @@ #include #include #include +#include #include #include #include @@ -1595,7 +1596,7 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len) err = -ENODEV; goto out; } - if (dev->type != ARPHRD_CAN) { + if (!can_get_ml_priv(dev)) { err = -ENODEV; goto out_put_dev; } @@ -1895,7 +1896,7 @@ static int isotp_notifier(struct notifier_block *nb, unsigned long msg, { struct net_device *dev = netdev_notifier_info_to_dev(ptr); - if (dev->type != ARPHRD_CAN) + if (!can_get_ml_priv(dev)) return NOTIFY_DONE; if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN) return NOTIFY_DONE; diff --git a/net/can/raw.c b/net/can/raw.c index 9f0fa8baff85..26c8cf15d60e 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -49,6 +49,7 @@ #include #include #include +#include #include #include /* for can_is_canxl_dev_mtu() */ #include @@ -343,7 +344,7 @@ static int raw_notifier(struct notifier_block *nb, unsigned long msg, { struct net_device *dev = netdev_notifier_info_to_dev(ptr); - if (dev->type != ARPHRD_CAN) + if (!can_get_ml_priv(dev)) return NOTIFY_DONE; if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN) return NOTIFY_DONE; @@ -486,7 +487,7 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) err = -ENODEV; goto out; } - if (dev->type != ARPHRD_CAN) { + if (!can_get_ml_priv(dev)) { err = -ENODEV; goto out_put_dev; }