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=1794273488; b=PSOhVEgnt8u6D8vg0QVhCUVTxyp4bzt1GTot5GwEF/nbXbpJlFevJiGZHLBmqwFCc/Am oI2Hp3d0BxS4YG/Cr3B3xsQu0jMbe1BI4ooxoZtssUnBpA86lX3DG3J/x9qNbdFQarA5x dofJYjaXJFSYcqvfz2/d9ZbtUooGKn6xvx24InZTKW2/qc9xI5ykCcIjyWQLlrJokp8jJ QTrRtkpXTnSW/u/VWHiXshwm7DakNOvilBRxdM7DgLk0J7H/DY+YKITBtCVXrejqXyiH7 +cuCHaXGBPHM2wnZkEf2ZE1a3ioIGAPYT9idAw3z25WKG3c4VtToBv90c72jofw3mXA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794273488; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=H2qvv2azUlOOuBlxB0OcoATDqG+r1/XYOc1un8urNj4=; b=3xRI2Y49/ONi0sI/a+i1PEQYnKqiQThZ60hIblcu1i/M04w75GZSMHLyP1tzquY65Ow+ u8PEEFYyaxIxRHnF2CQPWinLoFob0PqcDMkxE5nAOIsuLH0VRN6i6CETPPrubj+mOGEJr 5l3ub7d1UezqJVN4pRF8PMKLRtYpmtEHONRuc2VixKUfXTse1Z41gbOPcAskmK67/VJL3 zTky60gdQ/7OkDMzOvQS/fHiMGj8ZbZIu0miIMoEX716ppnvdansas/n90wwgsXUNYPmi nc8DkxDbz0PT0o54FnOwruAiKry7DhHPEFg0vNBosOLuu2yJqh197+chA5GIVH+MdPg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Pwtn1l3g; 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 258C6606A31C for ; Tue, 10 Nov 2026 01:18:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Pwtn1l3g Received: by smtp.kernel.org (Postfix) with ESMTPSA id 585641F0089F; Tue, 10 Nov 2026 01:18:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794273487; bh=H2qvv2azUlOOuBlxB0OcoATDqG+r1/XYOc1un8urNj4=; h=From:To:Cc:Subject:Date; b=Pwtn1l3gprOAKCgjUnvmia1gD/OcrHrhMhdO6uNaIpeFZusLxve+zLIcChkPYi+Lt DlItT8hi4mG70GuFH6g5V9cx23gntU9VryFAytqeaNfFnmNIMw6oikGRMBxhm+s9gB FZLW/wZSzYMu2J4j3VXRC0WJlr+fKA2sOZiBa6wipA4YJa85vX4XAoaH4PpdRNybZy fFnfgbCpEHVxKGvxX1YYZc4vbhRvCngSPKPHgN1dsc04Sx9yO+ydyM5opdcIXRFrOa S2k9s2A7bNsDs8btxiN5ztBGlPTN6vlfOXj2BNpvJAOtqT1oUQp9R0MuhnZPHaU1fq AeubJLi3x0I3w== From: Sasha Levin To: mailhol@kernel.org, mkl@pengutronix.de Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] can: dev: can_dropped_invalid_skb: drop CAN XL frames on non-CAN XL devices" failed to apply to 6.1-stable tree Date: Mon, 9 Nov 2026 20:18:06 -0500 Message-ID: <20261109201806-failed-6.1-0fce44e29fce@kernel.org> X-Mailer: git-send-email 2.53.0 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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 0fce44e29fce4b07642491b098afb41bd571e4f2 # git commit -s git send-email --to '' --in-reply-to '20261109201806-failed-6.1-0fce44e29fce@kernel.org' --subject-prefix 'PATCH 6.1.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 0fce44e29fce4b07642491b098afb41bd571e4f2 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Fri, 31 Jul 2026 18:29:44 +0200 Subject: [PATCH] can: dev: can_dropped_invalid_skb: drop CAN XL frames on non-CAN XL devices 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 --- 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