From nobody Thu Apr 2 17:11:22 2026 Received: from mxout70.expurgate.net (mxout70.expurgate.net [194.37.255.70]) (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 E68092D3EE5; Fri, 27 Mar 2026 08:49:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.37.255.70 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774601355; cv=none; b=Dxy/JHboRqo3+OaQrADyOLtJ/AOzGqlanf0nXx06h65bXPuu8NmHpv8wO3yBJl8Vzz0ASe7XTnZwjZEQxEwYLuGql0RKsPDqfJKm0r7ehXrItLMeLKtGeubfIu3lMVDlCirPUKXxHTT5c/6H+Kln/MHl0gbVSo4yeGt8fDxnhsY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774601355; c=relaxed/simple; bh=AszbKk2UbW/3YlByw22wCgCrsW1o6pJgrdRCwlXFd3A=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:To:Cc; b=hkeGw8conn8izw0nSQYghbZR+/2kvdMqP7O8V0vU5Ofsu4Bat8WlUmv1U2yQeptplud8YrvvAeDHOZ/fi/azDX5XodEI99LLc9ZD7diOOTmtxuA5kjU5bk0SptEg1YQhlRw1iSEQOjNXlwowAWAgNCf0nPoY5n+kuWDlE3ZkuoY= 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=rnwaK1a9; arc=none smtp.client-ip=194.37.255.70 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="rnwaK1a9" Received: from [194.37.255.9] (helo=mxout.expurgate.net) by relay.expurgate.net with smtp (Exim 4.92) (envelope-from ) id 1w62sN-00GYrU-Hn; Fri, 27 Mar 2026 09:49:07 +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 1w62sM-002zRG-Ol; Fri, 27 Mar 2026 09:49:06 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dev.tdt.de; s=z1-selector1; t=1774601346; bh=myEI14OaJ5vlN9nRaS+DEQwHA9TNMsxy8cNQZpWUwc8=; h=From:Date:Subject:To:Cc:From; b=rnwaK1a94NT1Y4Ih9vi85yyVImKmUnF1ZU+yXg1Nb4SbVBBxMJHefQmZilzlhg1Vl BJgHjIGegqfmwtzX3aLLbu3zhJ7jk6IfZBN51HU7fZ32rXhAFyrYa54TRiL0ulJA/c WdadSANtAsBCdzYYrF1d6iGx3soFEYzxVHXnxbT860wims7oM6sG5/bnMyJRFVLEO3 Z8MJn8+manKu6yqalpYEjEmqvXKBy1wKAFH+HGyoAbGAJCgN1skoW3lTIRaTUxp8Y1 65S5naBfwx+uVUAkQ7CEeaiDZO4bUZZw38Fv/49iwy6Fcs8SH4H6IgkN5Ts65RR2d7 4iZXubjxxThMQ== Received: from securemail.tdt.de (localhost [127.0.0.1]) by securemail.tdt.de (Postfix) with ESMTP id 26D1F240040; Fri, 27 Mar 2026 09:49:06 +0100 (CET) Received: from mail.dev.tdt.de (unknown [10.2.4.42]) by securemail.tdt.de (Postfix) with ESMTP id 19281240036; Fri, 27 Mar 2026 09:49:06 +0100 (CET) Received: from [127.0.1.1] (unknown [10.2.3.19]) by mail.dev.tdt.de (Postfix) with ESMTPSA id E46E3210AC; Fri, 27 Mar 2026 09:49:05 +0100 (CET) From: Martin Schiller Date: Fri, 27 Mar 2026 09:49:02 +0100 Subject: [PATCH net v2] 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-v2-1-143911c3f62a@dev.tdt.de> X-B4-Tracking: v=1; b=H4sIAH1ExmkC/1WNQQrDIBRErxL+ugY12rRd9R4llOD/JkIxRUVSg nevSDddvhnmzQGRgqMIt+6AQNlFt/kK8tSBWWe/EHNYGSSXZz5IzXapnzbMy4s8u1gjFUdBiAP UxTuQdXuzPcBTgqmGq4tpC5/2kEWrfrLxT5YFE+xqzagFKjtqdUfKfcLUI8FUSvkCLfOgo6wAA AA= 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=1774601345; l=1712; i=ms@dev.tdt.de; s=20260220; h=from:subject:message-id; bh=AszbKk2UbW/3YlByw22wCgCrsW1o6pJgrdRCwlXFd3A=; b=qOX6IEPtyPoTNmSlCc6CCNmXY5l+QjdKavO7qtzQ5LjkoyQkHd2sluFSAGu/lbR5MOxC5oyCl inno2UZB/BkC40gTNo+Y7d0adtR1qK6TKoRrpBbM0oDTLdMnr+LTUhc X-Developer-Key: i=ms@dev.tdt.de; a=ed25519; pk=MAojd7D5IafMnqCYSFC7hY/u/jppX58CLIEhsEsSOYE= X-purgate-type: clean X-purgate: clean X-purgate-ID: 151534::1774601347-A6786013-7F5441A1/0/0 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 --- Changes in v2: - Use USHRT_MAX instead of sizeof(fraglen) nonsense - Link to v1: https://lore.kernel.org/r/20260327-x25_fraglen-v1-1-9fc751d4f= 754@dev.tdt.de --- 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..cb84c683d249d6078f3673835bb= 2f80eb487f253 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 > USHRT_MAX) { + 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