From nobody Fri Apr 3 03:00:10 2026 Received: from cstnet.cn (smtp25.cstnet.cn [159.226.251.25]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8CA71382394; Wed, 25 Mar 2026 07:42:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.25 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774424529; cv=none; b=obxISa9oAR+b4z2qnCha4z357HtT4FXHIqKt/LaCJAt6HOMJWM/Q87r2LAdoQDeWMuyrxqk5qkfBboJ5M+qy3qLcOQXvXW+wDA3RX0zoR2Pg/r9VkYYBRAVnRAmcLKisPIdyZd5/ijx08wtoK/Lxmk+Y/hxz2NPJxlGXvRRboAY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774424529; c=relaxed/simple; bh=UCcLxBo5DmyQB8qL6xdFcENHbnFfl/F5Zzx+9T5RRhI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=t4IV7L5ZtPJwSIoyZeZ05KScZpac7gf47rx6TEJF5k4wytCpHFxTIzyU9MPw5VAkkDsHMKvsivXs4LvGgpzePlRfQ1sFz83lbt8NHagvPC4MZ/RO1HTmQrfDGI/02PBrVyImg3dBWZOF0Zb2V/RlyEx4SJBFRYmBZop7BIQFYSM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.25 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from localhost.localdomain (unknown [111.196.245.197]) by APP-05 (Coremail) with SMTP id zQCowAAXpgnAkcNpzB1uCw--.28929S2; Wed, 25 Mar 2026 15:41:52 +0800 (CST) From: Pengpeng Hou To: Justin Iurman , "David S . Miller" , David Ahern , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, pengpeng@iscas.ac.cn Subject: [PATCH] net/ipv6: ioam6: prevent schema length wraparound in trace fill Date: Wed, 25 Mar 2026 15:41:52 +0800 Message-ID: <20260325074152.17064-1-pengpeng@iscas.ac.cn> X-Mailer: git-send-email 2.50.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: zQCowAAXpgnAkcNpzB1uCw--.28929S2 X-Coremail-Antispam: 1UD129KBjvJXoW7KF1DXw15uFy8uF4xuw4rKrg_yoW8GFWfpF n8Kw13XFWDKFW8Kr1j9F45Jr1a9Fs5AFW3KFy5Aw1rKr1DGF10qFyrK3yruan8CrZ7GFWa vFyqyw17Wrn8ZaUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9014x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26ryj6F1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_Cr1j6rxdM28EF7xvwVC2z280aVCY1x0267AKxVW0oV Cq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628v n2kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7x kEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E 67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCw CI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1x MIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIda VFxhVjvjDU0xZFpf9x0JUd-B_UUUUU= X-CM-SenderInfo: pshqw1xhqjqxpvfd2hldfou0/ Content-Type: text/plain; charset="utf-8" ioam6_fill_trace_data() stores the schema contribution to the trace length in a u8. With bit 22 enabled and the largest schema payload, sclen becomes 1 + 1020 / 4, wraps from 256 to 0, and bypasses the remaining-space check. __ioam6_fill_trace_data() then positions the write cursor without reserving the schema area but still copies the 4-byte schema header and the full schema payload, overrunning the trace buffer. Keep sclen in an unsigned int so the remaining-space check and the write cursor calculation both see the full schema length. Fixes: 8c6f6fa67726 ("ipv6: ioam: IOAM Generic Netlink API") Signed-off-by: Pengpeng Hou Reviewed-by: Justin Iurman --- net/ipv6/ioam6.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv6/ioam6.c b/net/ipv6/ioam6.c index b76f89d92e7b..3978773bec42 100644 --- a/net/ipv6/ioam6.c +++ b/net/ipv6/ioam6.c @@ -708,7 +708,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb, struct ioam6_namespace *ns, struct ioam6_trace_hdr *trace, struct ioam6_schema *sc, - u8 sclen, bool is_input) + unsigned int sclen, bool is_input) { struct net_device *dev =3D skb_dst_dev(skb); struct timespec64 ts; @@ -939,7 +939,7 @@ void ioam6_fill_trace_data(struct sk_buff *skb, bool is_input) { struct ioam6_schema *sc; - u8 sclen =3D 0; + unsigned int sclen =3D 0; =20 /* Skip if Overflow flag is set */ --=20 2.50.1 (Apple Git-155)