From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794585678; b=EZ7/lY6mUSfqiGNB6NivN8zQK8mO8zx2SneBATOgDBGVGA4S5gsAby99dUJYlbxdpZs7 YAJtogaEEQqJK6yIHUD+5van7Y3S9uF7RMqZNdTySApsPN0YI9ZgDzLeAIHwmCBsF40N1 0y7kAEwe3w6E6iah8TJURyS6UPWHU+aF434k9O4bRFoRGCdtj5IBQWdj8JpFim5xWz1O/ giSvy7YlCcUBpqtBP1RfNFkaXWWmIxTLeaKoVBvZE9vbabBgS/1XeLJG3o4O+pZm1rw2K SZY/5gGzGpXkFSQNzRkCIUBr+/aR1/XBnwrHDYY4GGA2n093/HpzoRzCLw5pTX50GFg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794585678; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=jWTnN7J6moXnAEk0BdyttRhh1OAm40FAJokymRqkAd4=; b=eG4hPS2ZgrMSoJj562XWmq4HXkefg76Qwb1+YpfC4X1vJjbaZUMFnuLPa3lnjLtizUom au94Gd0jdv0wtWEznntKnnRvt/CYbMPUQhS+2uB6aF5tbgZFWVrqc0IL1syAOSjIQRPGz gK7o2Cqonbs82At2Q07+aedpA0OUl/cWXGnxXA1s1ngzsunF35CojU/7jYaVLbjVprsOE XuTVAIIqBlVFzEYCHrbO5dSl6DHOKnSllEHOUJ0fJba+0bYlOG1G5E+Gau5p2zQsqjvXo BKuOJgKD2Q/HKI1uGMxji6Nu+hs73HaAqF+JueKkfDu8qZd/BzYoDmujaRT+tPna0Qw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=afIaqaR2; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F21C560744DB; Fri, 13 Nov 2026 16:01:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=afIaqaR2 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9956D1F000C4; Fri, 13 Nov 2026 16:01:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794585677; bh=jWTnN7J6moXnAEk0BdyttRhh1OAm40FAJokymRqkAd4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=afIaqaR2xQwvTx/yMLokTgw5c5WjGCV6kySkNZYZXQTF4ZhE8u/qZvE6poxKRXPWo gIUCow8zm+jqVDfLU2c0Ivld2iAkw4Z2nhXSzCZa9oOYAcy0Xtt93bRaTCxfJ5U6Rp HbLVnAlD41d44QTZ+QkqQhiM1Ew7fLOQMP0FfsyY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Vincent Mailhol , stable@kernel.org, Marc Kleine-Budde , Sasha Levin Subject: [PATCH 7.3 290/507] can: dev: can_dropped_invalid_skb: drop CAN XL frames on non-CAN XL devices Date: Fri, 13 Nov 2026 10:49:54 -0500 Message-ID: <20261113153805.086829308@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153753.358973689@linuxfoundation.org> References: <20261113153753.358973689@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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 7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vincent Mailhol [ Upstream commit 0fce44e29fce4b07642491b098afb41bd571e4f2 ] Sending a PF_PACKET bypasses the CAN framework logic and can directly reach a CAN driver's xmit() function. The PF_PACKET framework only checks that skb->len does not exceed the net_device MTU. For a CAN device that is not CAN XL capable, anything above CANFD_MTU (72 bytes) is therefore dropped before it reaches the driver. However, CAN XL frames are variable length. can_is_canxl_skb() accepts lengths in the range CANXL_HDR_SIZE + CANXL_MIN_DLEN up to CANXL_MTU, i.e. 13 to 2060 bytes. As a result, an ETH_P_CANXL skb with a length between 13 and 72 bytes can pass both the MTU and the can_dropped_invalid_skb() checks. A driver that does not support CAN XL will interpret canxl_frame->flags as a length because of the overlap with can_frame->len. And because CANXL_XLF is set, the resulting length is between 128 and 255. For drivers that do not check can_frame->len before copying can_frame->data, as most drivers do, this results in a buffer overflow of up to 247 bytes. Drop ETH_P_CANXL skbs if the device does not have the CAN_CAP_XL capability. Keep can_is_canxl_skb() for the validation of CAN XL skbs. Closes: https://sashiko.dev/#/patchset/20260731-master-v5-0-5b27029dee20@qq.com?part=1 Fixes: fb08cba12b52 ("can: canxl: update CAN infrastructure for CAN XL frames") Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20260731-drop_canxl_frames-v1-1-7387b70353b3@kernel.org Cc: stable@kernel.org Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- drivers/net/can/dev/skb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c index 14edec5afb57e..bc0787535b524 100644 --- a/drivers/net/can/dev/skb.c +++ b/drivers/net/can/dev/skb.c @@ -4,6 +4,7 @@ * Copyright (C) 2008-2009 Wolfgang Grandegger */ +#include #include #include #include @@ -388,7 +389,7 @@ bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb) break; case ETH_P_CANXL: - if (!can_is_canxl_skb(skb)) + if (!can_cap_enabled(dev, CAN_CAP_XL) || !can_is_canxl_skb(skb)) goto inval_skb; break; -- 2.53.0