From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mo4-p01-ob.smtp.rzone.de (mo4-p01-ob.smtp.rzone.de [81.169.146.165]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F4073485516 for ; Mon, 19 Oct 2026 07:43:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=81.169.146.165 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792395798; cv=pass; b=MiCK5KZ0W7LvOTaVMS6D5csOKaUVAR2BkUR7KPBOjI0Y6vZkzBadsvAOsFvVk/kZ4xGTRLUjrshh9t+D2TfRV2N2h7VlIGP3W1ydejy4h1Uo66Nv2lz+q6IGRWwqCN49ixMJ17oTxHMY6uYhcEdHP8TOYOn4Fto/EISvwIAQ9zg= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792395798; c=relaxed/simple; bh=dNdZxKmDbdzoNXBIRB3FP8m2nl7ZVtdpCFI/Ca/ZYTQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=PBiMJY4uILVASJW3uduQY8UsEIIRQEKR201OJdOR+XudB7Hs4/c7C33i9KyOlk80VNPQU7Z271N4chN1G5+Rl2Rfr0yzw+dfYGJMIPn5W2XD68bpjtBDSvSzZD1f6OCb1x8MdLQuf1jOJK67RIkdZbDgqvUXvRYnLYVo7GDj9LQ= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=hartkopp.net; spf=fail smtp.mailfrom=hartkopp.net; dkim=pass (2048-bit key) header.d=hartkopp.net header.i=@hartkopp.net header.b=L0Vfj7EX; dkim=permerror (0-bit key) header.d=hartkopp.net header.i=@hartkopp.net header.b=BTT2JcIP; arc=pass smtp.client-ip=81.169.146.165 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) header.d=hartkopp.net header.i=@hartkopp.net header.b="L0Vfj7EX"; dkim=permerror (0-bit key) header.d=hartkopp.net header.i=@hartkopp.net header.b="BTT2JcIP" ARC-Seal: i=1; a=rsa-sha256; t=1792395776; cv=none; d=strato.com; s=strato-dkim-0002; b=SnMjJdAtHl2a898lh/hkWhP5aQegxTyrCbCXDjFSIW2xdeSU887/3Z5WAvwUbEp2fV zDNzJz8F6tUyBe8bnMNlEKAxbAsLiGErku8Pde1bYHM3aKip/roo+usljM7eHZLCvbh4 UJY8E9mJwb0vfymy5QDn5nJFZ6/AFy68eAW13DGnBaf+xDg655qOVWUamypJAWBdzqjX CZy/rt9CdcHnlZlcPoaWJMs7K5/dClKqww5bUNNXplwv1F7b1Qcnyj/VkmBDrCVoUE1w K+TViaRyicmbFNw3qxB4m2Ryc3ONkL1bPfXvjcListfsMmtBfo5hnc2q7zpoKDna2Bst RV+g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; t=1792395776; 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=YWDd2qurMnD006MRi+qUpYPSzmrbQkmIXCOOkyQKsPQ=; b=N8vWGVw6qKr7siQC4XS3tnUeW61m5jrVtb4MKk/IqUvDe/j1G5WFgQEGOhcsdGnQUt 0tuxTw7cR6cXM2iEkMOriag4yJbXzjip7UcJzgMSIWY1giFvwxFc/t8Pd/U8QUC1F+jh 0uHEbIPMdWIJ9vqLHmq6o03Ubt1C+XKp447AW8UgT+hx+lAIn2zTfmLCJ//a3AYr7eEC NXESdD2oYzJx9k2C7PWyfh8/CtG98RzqA8XBZ8bTOXMA4g8UjaUbS329i6Cz5puJdXEN S599Yf4OQ+jHWD4S7g20TefWLkuPgnpXAH2RRkcH0upwogksovrN7XXPi8HnRK2jY0tg o5xw== ARC-Authentication-Results: i=1; strato.com; arc=none; dkim=none X-RZG-CLASS-ID: mo01 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1792395776; 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=YWDd2qurMnD006MRi+qUpYPSzmrbQkmIXCOOkyQKsPQ=; b=L0Vfj7EXuXja4tfxS8cA/v/fVuFeZDMDPJHUqWOgVnWKMwMy3fUFigv2YC9sa0X1h+ ZmXhT0khgVZyQXC6JaGDoLabkh5MO2u11dggmr0W20XSIY2oyo4iPBvWHsJS7/v6Yn4c rFPipG2v80XdPyhIhef0GOcRkGtRHMJuDJGdCWYX5+OXiHXR7X7mTyVP5R5kjdXdPV9q h4naN0nmWt7qSnKZ7/ZhRjJgZZ2xPZ6w/v3Nte/RGxPOK11Wk/1Tym751uBgEOj9iHNF 4y8/NFK9pjQBBdYJIYte2tqX1Gy2uatxuoMb+wTsHr9EboRQti75inl2lLC/uvkt7CJH Gj/A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; t=1792395776; 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=YWDd2qurMnD006MRi+qUpYPSzmrbQkmIXCOOkyQKsPQ=; b=BTT2JcIPoUAk/dc5b63J7xPCcyAb5h+YteYzDDaGrhRbKHjw34ZqCr8Xuiyz2dFVR7 aRfvH4UhdwMfK9a3OUBw== X-RZG-AUTH: ":P2MHfkW8eP4Mre39l357AZT/I7AY/7nT2yrDxb8mjH4JKvMdQv2tTUsMrZpkO3Mw3lZ/t54cFxeEQ7s8bDup0Q==" Received: from vivo.lan by smtp.strato.de (RZmta 55.6.3 AUTH) with ESMTPSA id Kfdf2a29J7guUqF (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Mon, 19 Oct 2026 09:42:56 +0200 (CEST) From: Oliver Hartkopp To: linux-can@vger.kernel.org Cc: Oliver Hartkopp , stable@kernel.org, Oleksij Rempel , Marc Kleine-Budde Subject: [PATCH can-next v3 3/4] can: replace ARPHRD_CAN type checks with can_get_ml_priv() Date: Mon, 19 Oct 2026 09:42:42 +0200 Message-ID: <20261019074244.50391-4-socketcan@hartkopp.net> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261019074244.50391-1-socketcan@hartkopp.net> References: <20261019074244.50391-1-socketcan@hartkopp.net> Precedence: bulk X-Mailing-List: linux-can@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="us-ascii" 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 and triggers a NULL pointer dereference when CAN filters are created and when they are removed, e.g. by the CAN protocols' netdevice notifier handlers. 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@kernel.org Cc: Oleksij Rempel Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20261012164802.94113-1-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde --- net/can/af_can.c | 15 ++++++--------- net/can/bcm.c | 7 ++++--- net/can/gw.c | 7 ++++--- net/can/isotp.c | 5 +++-- net/can/raw.c | 4 ++-- 5 files changed, 19 insertions(+), 19 deletions(-) diff --git a/net/can/af_can.c b/net/can/af_can.c index 6ebe9d3689ac..d97f85fc3232 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -224,11 +224,11 @@ int can_send(struct sk_buff *skb, int loop) if (unlikely(skb->len > READ_ONCE(skb->dev->mtu))) { err = -EMSGSIZE; goto inval_skb; } - if (unlikely(skb->dev->type != ARPHRD_CAN)) { + if (unlikely(!can_get_ml_priv(skb->dev))) { err = -EPERM; goto inval_skb; } if (unlikely(!(skb->dev->flags & IFF_UP))) { @@ -450,11 +450,11 @@ int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id, struct can_dev_rcv_lists *dev_rcv_lists; struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats; /* 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))) return -ENODEV; @@ -517,11 +517,11 @@ void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id, struct receiver *rcv = NULL; struct hlist_head *rcv_list; 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))) return; @@ -682,12 +682,11 @@ 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) { struct can_skb_ext *csx = can_skb_ext_find(skb); - if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || - !csx || !can_is_can_skb(skb))) { + if (unlikely(!can_get_ml_priv(dev) || !csx || !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); kfree_skb_reason(skb, SKB_DROP_REASON_CAN_RX_INVALID_FRAME); return NET_RX_DROP; @@ -708,12 +707,11 @@ 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) { struct can_skb_ext *csx = can_skb_ext_find(skb); - if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || - !csx || !can_is_canfd_skb(skb))) { + if (unlikely(!can_get_ml_priv(dev) || !csx || !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); kfree_skb_reason(skb, SKB_DROP_REASON_CANFD_RX_INVALID_FRAME); return NET_RX_DROP; @@ -734,12 +732,11 @@ 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) { struct can_skb_ext *csx = can_skb_ext_find(skb); - if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || - !csx || !can_is_canxl_skb(skb))) { + if (unlikely(!can_get_ml_priv(dev) || !csx || !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); kfree_skb_reason(skb, SKB_DROP_REASON_CANXL_RX_INVALID_FRAME); return NET_RX_DROP; diff --git a/net/can/bcm.c b/net/can/bcm.c index 6c85a76477c3..6759662e024c 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -52,10 +52,11 @@ #include #include #include #include #include +#include #include #include #include #include #include @@ -1716,11 +1717,11 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) if (!dev) { ret = -ENODEV; goto out_release; } - if (dev->type != ARPHRD_CAN) { + if (!can_get_ml_priv(dev)) { dev_put(dev); ret = -ENODEV; goto out_release; } @@ -1864,11 +1865,11 @@ static void bcm_notify(struct bcm_sock *bo, unsigned long msg, static int bcm_notifier(struct notifier_block *nb, unsigned long msg, void *ptr) { 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; if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */ return NOTIFY_DONE; @@ -2021,11 +2022,11 @@ static int bcm_connect(struct socket *sock, struct sockaddr_unsized *uaddr, int dev = dev_get_by_index(net, addr->can_ifindex); if (!dev) { 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 36f9aa0f7026..8a5327d8a00e 100644 --- a/net/can/gw.c +++ b/net/can/gw.c @@ -50,10 +50,11 @@ #include #include #include #include #include +#include #include #include #include #include #include @@ -610,11 +611,11 @@ static int cgw_notifier(struct notifier_block *nb, unsigned long msg, void *ptr) { 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) { struct cgw_job *gwj = NULL; struct hlist_node *nx; @@ -1161,19 +1162,19 @@ static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh, gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx); 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); 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? */ if (gwj->src.dev == gwj->dst.dev && !(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK)) { diff --git a/net/can/isotp.c b/net/can/isotp.c index b239f4b45518..1a272ce6a2bd 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -63,10 +63,11 @@ #include #include #include #include #include +#include #include #include #include #include #include @@ -1608,11 +1609,11 @@ static int isotp_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int l dev = dev_get_by_index(net, addr->can_ifindex); if (!dev) { err = -ENODEV; goto out; } - if (dev->type != ARPHRD_CAN) { + if (!can_get_ml_priv(dev)) { err = -ENODEV; goto out_put_dev; } if (READ_ONCE(dev->mtu) < so->ll.mtu) { err = -EINVAL; @@ -1895,11 +1896,11 @@ static void isotp_notify(struct isotp_sock *so, unsigned long msg, static int isotp_notifier(struct notifier_block *nb, unsigned long msg, void *ptr) { 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; if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */ return NOTIFY_DONE; diff --git a/net/can/raw.c b/net/can/raw.c index 98808a75212e..09a5c0275ae6 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -346,11 +346,11 @@ static void raw_notify(struct raw_sock *ro, unsigned long msg, static int raw_notifier(struct notifier_block *nb, unsigned long msg, void *ptr) { 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; if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */ return NOTIFY_DONE; @@ -489,11 +489,11 @@ static int raw_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int len dev = dev_get_by_index(sock_net(sk), addr->can_ifindex); if (!dev) { err = -ENODEV; goto out; } - if (dev->type != ARPHRD_CAN) { + if (!can_get_ml_priv(dev)) { err = -ENODEV; goto out_put_dev; } if (!(dev->flags & IFF_UP)) -- 2.43.0