From nobody Thu Apr 2 17:10:49 2026 Received: from mxout70.expurgate.net (mxout70.expurgate.net [91.198.224.70]) (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 3BBE72FF155; Fri, 27 Mar 2026 08:50:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.198.224.70 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774601454; cv=none; b=fWYUg6w6hJl/zGUWTIma6ZHxmP73JM5ct/0mSpNk7vmGp47nJHNtnaa9sS+DArFJwzhUG0i34I38X6v8/cKwUGTpY9mEviyZGlHcoB3WPq8/NaEPWfHN74oAStrGhzZsoQMPjF6vXYTBHoQhhxG2umzC7ovKVGKQW0Q3Uuqk47Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774601454; c=relaxed/simple; bh=z6z7xz+iqeiIUkPQLjGp8WavFPeWOi1bzCahE5cQY4Q=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:To:Cc; b=nQCjoF4ubYXcT+g9QGX5M9TbKOgJhpTrOHLYtTpMBvXbuN/qPGB1KT2R23ZsWkMmhWrG8xb4Eu4fgeNhq4qXXLHJgRtEEpteGwKHepYZcsaXJ5EXn7KKl6n+jM2it4bluh/yapO2sUuxnryuMwjtudJ0HDjy0eUTHcYM6pBgFsU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=dev.tdt.de; spf=pass smtp.mailfrom=dev.tdt.de; dkim=temperror (0-bit key) header.d=dev.tdt.de header.i=@dev.tdt.de header.b=fq9CBLy5; arc=none smtp.client-ip=91.198.224.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=dev.tdt.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=dev.tdt.de Authentication-Results: smtp.subspace.kernel.org; dkim=temperror (0-bit key) header.d=dev.tdt.de header.i=@dev.tdt.de header.b="fq9CBLy5" Received: from [194.37.255.9] (helo=mxout.expurgate.net) by relay.expurgate.net with smtp (Exim 4.92) (envelope-from ) id 1w62av-00BrUV-9x; Fri, 27 Mar 2026 09:31:05 +0100 Received: from [195.243.126.94] (helo=securemail.tdt.de) by relay.expurgate.net with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1w62au-00G6dA-7N; Fri, 27 Mar 2026 09:31:04 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dev.tdt.de; s=z1-selector1; t=1774600263; bh=C4yTxAHTn4We4DXR/M9YLhr/wzuzBi4JfHbMXvbdvvY=; h=From:Date:Subject:To:Cc:From; b=fq9CBLy52WS8J2xkYaB9/wUthXI39N6exb5gsCJS9GXwinakRxrwxfKGH3+sYU1uu b4KX3lHQyroTfw2pjhFaaQsBrzkMBfA+b1EKsRlHJjpuSe+Z/Q6Pr4kDtmGo43MHIs HRhXRBYciiKbX5XCqpiaezGX9O5CMnTs8srFUGf7a6WJDdq9Gg9cl+p+sceLfM3Gie EwkCsLlJ9a9paZSbFmQKYwrvSrFLosTfi1gDZxn8XEAK0Ppnzztm2YSG0MiGd8sUi7 HUZ5WZpSzfrOisg8bPB6/wXEKHluMZGgRPknfkHRRRUrVOpoqsKGIoQJhhSwLAUC20 POIkIyEzlXk7A== Received: from securemail.tdt.de (localhost [127.0.0.1]) by securemail.tdt.de (Postfix) with ESMTP id ACC7C240040; Fri, 27 Mar 2026 09:31:03 +0100 (CET) Received: from mail.dev.tdt.de (unknown [10.2.4.42]) by securemail.tdt.de (Postfix) with ESMTP id A37B5240036; Fri, 27 Mar 2026 09:31:03 +0100 (CET) Received: from [127.0.1.1] (unknown [10.2.3.19]) by mail.dev.tdt.de (Postfix) with ESMTPSA id 772FA21860; Fri, 27 Mar 2026 09:31:03 +0100 (CET) From: Martin Schiller Date: Fri, 27 Mar 2026 09:30:58 +0100 Subject: [PATCH net] net/x25: Fix overflow when accumulating packets Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-ID: <20260327-x25_fraglen-v1-1-9fc751d4f754@dev.tdt.de> X-B4-Tracking: v=1; b=H4sIAEFAxmkC/x3MQQqAIBBA0avErBN0rIiuEhGiow2EhUYE0t2Tl m/xf4FMiSnD1BRIdHPmI1aotgG7mRhIsKsGlDhIjb14sF99MmGnKEZvsZNOkXMaanEm8vz8txk iXbC87wfPDl2eYgAAAA== X-Change-ID: 20260325-x25_fraglen-8fc240d1edd3 To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Yiming Qian , linux-x25@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, security@kernel.org, Martin Schiller X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1774600263; l=1558; i=ms@dev.tdt.de; s=20260220; h=from:subject:message-id; bh=z6z7xz+iqeiIUkPQLjGp8WavFPeWOi1bzCahE5cQY4Q=; b=MAENNjzRNYxobCk23Ax+85809q/FlI10zF/+LPF36Deh8nYvaTym8fULiXoOD8xPazVO9fN/y 1wEfC9SjR1nCSiSluu9HUUkxAsV6iU0JJyeQcxdXAqYkZ67Nm9YatiT X-Developer-Key: i=ms@dev.tdt.de; a=ed25519; pk=MAojd7D5IafMnqCYSFC7hY/u/jppX58CLIEhsEsSOYE= X-purgate: clean X-purgate-ID: 151534::1774600264-E54ACBD2-3D888FAF/0/0 X-purgate-type: clean Add a check to ensure that `x25_sock.fraglen` does not overflow. The `fraglen` also needs to be resetted when purging `fragment_queue` in `x25_clear_queues()`. Reported-by: Yiming Qian Signed-off-by: Martin Schiller --- net/x25/x25_in.c | 6 ++++++ net/x25/x25_subr.c | 1 + 2 files changed, 7 insertions(+) diff --git a/net/x25/x25_in.c b/net/x25/x25_in.c index b981a4828d08c2e6676749a06035910eab01e6cd..1603238d6fff73090ef10b5fd11= 387b3e7f017a2 100644 --- a/net/x25/x25_in.c +++ b/net/x25/x25_in.c @@ -34,6 +34,12 @@ static int x25_queue_rx_frame(struct sock *sk, struct sk= _buff *skb, int more) struct sk_buff *skbo, *skbn =3D skb; struct x25_sock *x25 =3D x25_sk(sk); =20 + /* make sure we don't overflow */ + if (x25->fraglen + skb->len > sizeof(x25->fraglen)) { + kfree_skb(skb); + return 1; + } + if (more) { x25->fraglen +=3D skb->len; skb_queue_tail(&x25->fragment_queue, skb); diff --git a/net/x25/x25_subr.c b/net/x25/x25_subr.c index 0285aaa1e93c17233748d38eef6d8b5c6059b67a..159708d9ad20cb2e6db24ead67d= af1e9d6258f64 100644 --- a/net/x25/x25_subr.c +++ b/net/x25/x25_subr.c @@ -40,6 +40,7 @@ void x25_clear_queues(struct sock *sk) skb_queue_purge(&x25->interrupt_in_queue); skb_queue_purge(&x25->interrupt_out_queue); skb_queue_purge(&x25->fragment_queue); + x25->fraglen =3D 0; } =20 =20 --- base-commit: 4ae97cae07e15d41e5c0ebabba64c6eefdeb0bbe change-id: 20260325-x25_fraglen-8fc240d1edd3 Best regards, --=20 Martin Schiller