From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=pass header.oldest-pass=0 smtp.remote-ip=85.215.255.84 ARC-Seal: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=pass; t=1794333928; b=29pvsGjw8SbXOyhXNgJWanGj3PuP+03SMzbefyDQkCYScHhm4D3zSPAh6XwEAxaySAdD 5wGXCNzOlWqk2iII1zCTw7dXB7nIILVLXGAg/pvKEnNYUSxu7SJaOK4iAGClVYydwW4BK sqvvpprJJH1/9beRMmSiIF8CiwP0g2omBu4qfNrlVUi799x/qpO0S7HRaciku6uZvZLWN 9NosuYsuJUZa89/nCy/MVctU2+m35PpUoNpyNAYtLpGzR9l1KYEtvhaf8j84tVxn3CToN wgM9SRT7Z0UvpWORIISiyPLobgsj30wP/n85MsnJni6GTlrqLN/bwgge9o5ZgWt4wow== ARC-Message-Signature: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794333928; 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=IcT9bEFQcCXGi0Yg9aoleYkfvUyKLbSL2CRn6eKdIWI=; b=J6nt6FjpgmI+bdWBcJNPJ1NA+VAJ7TsFFX0c/HT2uCy1ZAl0byJY//6GML1XUapkqi3A 74RXH965Vk5duvDecJViPsGotd4DiWwXXwwSAht6K2zHMUFsBMJRw0yHn2Vv2mY7W+HKt hTkbM+96NO46pmtktFe0IK2KmlzbbBjD25L88ixxTDgJJnk5Jyl5U/PHh8VXpScoqKYhW ABi8IA5ZgK8eQLiradljAdfS61dnZk821jWzaBz0rHVU9CuLZktapzFh2J/HiQX8K3XQ/ FWXtcUu7kwAyfv553eDTk2gILDoUo/bGQepXC5U0XBV/H6IZKUvmIAODCP6Q9xS5JhA== 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=cmShsZj0; dkim=pass header.d=hartkopp.net header.i=@hartkopp.net header.a=ed25519-sha256 header.s=strato-dkim-0003 header.b="BTKP/wIJ"; arc=pass header.oldest-pass=0 smtp.remote-ip=85.215.255.84 Received: from mo4-p02-ob.smtp.rzone.de (mo4-p02-ob.smtp.rzone.de [85.215.255.84]) (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 91A37606A325 for ; Tue, 10 Nov 2026 18:05:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 91A37606A325 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.a=rsa-sha256 header.s=strato-dkim-0002 header.b=cmShsZj0; dkim=pass header.d=hartkopp.net header.i=@hartkopp.net header.a=ed25519-sha256 header.s=strato-dkim-0003 header.b=BTKP/wIJ ARC-Seal: i=1; a=rsa-sha256; t=1794333911; cv=none; d=strato.com; s=strato-dkim-0002; b=oVo5Ea5HesIu5wdgCezWylePFiM9o9MnnKoThLErtnlyPBV6kjyQmpZPSfLWRdA8gu R+XgdAwhWSSlfuEBhCg3tT9UfWCh8r1Pi14nlecQyfYyFqdatU9iDAnXOaeVU+bbvWZm TjC12lz5mnnOrkYQFdGc76QtV/yzf5gIi4nzTYciCaV4dz5blQ9kJ7Ad7WvNxm/opLcx ydZ5YoNSKt9C9cr2yXruZo43R6S7otLtlTV/3vsx5WAzwZug4mQ45fFD7K1SRuMJ+7Rd 3y3lGGkH+vDVhPGe8U2pWgw+JNi3HYqmY+w4OJIg8NLGXWz2xfFF8e9oLzIx+EnHz/0K yV3w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; t=1794333911; 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=IcT9bEFQcCXGi0Yg9aoleYkfvUyKLbSL2CRn6eKdIWI=; b=YSn4FfRmjJpgKvddBUdQIlo0A6yQpdDAQadb+yN/9CnAebY+sSEgqnSh/ZAI4NPeRV ufAPnCt2jFqIMJQWhMEtkjDz18cicRKz7bgU1uho+iIqEMMFU51N3WSUYVG+NW53v25Y DqZAQN2shbDhokP77QEFnXwiWF5Ylx6dL06xBj+raWDUuDalM0tfEG7U6U6rAOfGwx5T KelCD+Ak6p+tN1tawh63Nph2uAz9UW47GU/swY+ppwwirkUZxBMvu/MNtnycHNv0kYpG iFlY2FooZVBtiqRacYG+QLmyFYJsJ9T4Ne6yGXUgWvfks4TX9B34EVw7RaV4L054EGNd META== ARC-Authentication-Results: i=1; strato.com; arc=none; dkim=none X-RZG-CLASS-ID: mo02 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1794333911; 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=IcT9bEFQcCXGi0Yg9aoleYkfvUyKLbSL2CRn6eKdIWI=; b=cmShsZj03FGolp/LRQqNLyCbv60NS35UrrsYGeExC5Vpwx8/sHYpTv8xf1NozTjBg3 zxYvwm77Gl9oZ/mH2rD0Z/jKYI1eoGFq7d3/k9JBdkqco1c6guW/ULHIrN/mrG+P0Qks XepG6eD/JHmjF+IiKAJ5Y9mcrq4soq/MoQz77xjU8gAdXWiCIF6nqqp4mYu8oLr3CvPE qCR3crjbSXEkZ9qJ1WT0dOc/jGCpCrJu5UdPB6trBrPMXF9Y3npi02qICG5gOkTFVKsZ PaPQxYGOqGLBDX5frMI7h01J9I14Z6tnAfYeVv2ghns55uEbts6f+A/l8Q0uAB4Mtmrj SfIQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; t=1794333911; 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=IcT9bEFQcCXGi0Yg9aoleYkfvUyKLbSL2CRn6eKdIWI=; b=BTKP/wIJjBU6I+3kNpgbctj+fRAllm2yyeaqINVneho9+sOYr93325AYUfWgKFd30z FO3nd/YxTjxGPAZg0IBQ== X-RZG-AUTH: ":P2MHfkW8eP4Mre39l357AZT/I7AY/7nT2yrDxb8mjH4JKvMdQv2tTUsMrZpkO3Mw3lZ/t54cFxeEQ7s8bDup0Q==" Received: from vivo.lan by smtp.strato.de (RZmta 55.6.3 AUTH) with ESMTPSA id Kfdf2a2AAI5B1dd (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Tue, 10 Nov 2026 19:05:11 +0100 (CET) From: Oliver Hartkopp To: stable@vger.kernel.org Cc: Sasha Levin , Marc Kleine-Budde , Oliver Hartkopp Subject: [PATCH 5.10.y 4/4] can: replace ARPHRD_CAN type checks with can_get_ml_priv() Date: Tue, 10 Nov 2026 19:04:56 +0100 Message-ID: <20261110180456.792270-4-socketcan@hartkopp.net> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261110180456.792270-1-socketcan@hartkopp.net> References: <20261109202741-failed-5.10-962947b69589@kernel.org> <20261110180456.792270-1-socketcan@hartkopp.net> 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 5.10: This tree has no can_skb_ext, so only the ARPHRD_CAN check is removed from the conditions in can_rcv() and canfd_rcv(). There is no canxl_rcv() in this tree. 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 | 10 +++++----- net/can/bcm.c | 7 ++++--- net/can/gw.c | 7 ++++--- net/can/isotp.c | 5 +++-- net/can/raw.c | 5 +++-- 5 files changed, 19 insertions(+), 15 deletions(-) diff --git a/net/can/af_can.c b/net/can/af_can.c index 05066662279d..8131992809bb 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -225,7 +225,7 @@ 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))) @@ -687,7 +687,7 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev, { struct canfd_frame *cfd = (struct canfd_frame *)skb->data; - if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || skb->len != CAN_MTU)) { + if (unlikely(!can_get_ml_priv(dev) || skb->len != CAN_MTU)) { pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n", dev->type, skb->len); goto free_skb; @@ -713,7 +713,7 @@ static int canfd_rcv(struct sk_buff *skb, struct net_device *dev, { struct canfd_frame *cfd = (struct canfd_frame *)skb->data; - if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || skb->len != CANFD_MTU)) { + if (unlikely(!can_get_ml_priv(dev) || skb->len != CANFD_MTU)) { pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n", dev->type, skb->len); goto free_skb; diff --git a/net/can/bcm.c b/net/can/bcm.c index f655764aae83..99abdd11f107 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -54,6 +54,7 @@ #include #include #include +#include #include #include #include @@ -1663,7 +1664,7 @@ 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; @@ -1811,7 +1812,7 @@ 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; @@ -1967,7 +1968,7 @@ 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 c6efa4830ce9..55605135ca58 100644 --- a/net/can/gw.c +++ b/net/can/gw.c @@ -52,6 +52,7 @@ #include #include #include +#include #include #include #include @@ -541,7 +542,7 @@ 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) { @@ -1092,7 +1093,7 @@ 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); @@ -1100,7 +1101,7 @@ 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; ASSERT_RTNL(); diff --git a/net/can/isotp.c b/net/can/isotp.c index d06a99ce8413..e4542fdf8431 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -65,6 +65,7 @@ #include #include #include +#include #include #include #include @@ -1550,7 +1551,7 @@ 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; } @@ -1850,7 +1851,7 @@ 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 3e2822707ed8..293e79aadd32 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -49,6 +49,7 @@ #include #include #include +#include #include #include #include @@ -315,7 +316,7 @@ 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; @@ -454,7 +455,7 @@ 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; }