From nobody Wed Apr 1 20:46:06 2026 Received: from cstnet.cn (smtp21.cstnet.cn [159.226.251.21]) (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 CA45144CF29 for ; Wed, 1 Apr 2026 16:03:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.21 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775059409; cv=none; b=e5wqAgr/8HU7GruYJ58nW4NEabckTDNqoQgP+IB7Kf9Tq6yytQ2+ODn/6g/K8Ilr11BMVNuTBmX3T2zcLybYaZMZ2ImBpHwC4R+tt2wEfN0s+Gj9K9nwc5XAraNZE7ofuSHx3D9JBuLJV/BOAYsjXWQZZ+BG1vkRCY+9TJjMHKg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775059409; c=relaxed/simple; bh=zQouy2uxJBNelolFwTIk9VgsJ89mA/7Rs16hBr79ozw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=pbkOi2Kn58zuL6GBwRuHRuqmxYsZY+fn2Ov+RFNjamLtuqIjkBnLYAs4yggU0xGQNw4EPh7C73WE3eMvKUDh9OQNdiQ7+EwYWEG9JSJv0c838ZTVzFwuNyne2YtuZAkYv2Yy5nSu2NXpMtPqqnttBffeEJVqzV5awU+B67woOjs= 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=159.226.251.21 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-01 (Coremail) with SMTP id qwCowABnC2fDQc1pzBThCw--.49325S2; Thu, 02 Apr 2026 00:03:16 +0800 (CST) From: Pengpeng Hou To: richard@nod.at Cc: anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net, linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, pengpeng@iscas.ac.cn Subject: [PATCH] um: reject out-of-range port channel numbers Date: Thu, 2 Apr 2026 00:03:15 +0800 Message-ID: <20260401160315.88534-1-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: qwCowABnC2fDQc1pzBThCw--.49325S2 X-Coremail-Antispam: 1UD129KBjvJXoW7Cr4DGF17ZF1xGw13ZF1fJFb_yoW8WrW3pF WYy342krZ3Ja1ay34UWa1Uu34Yq3W2yay29FykJ3sIvF1YvFyrWF4Ygwn0vFnrGFWxJFy0 vrsYva4IvF1UJaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkG14x267AKxVWUJVW8JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r4j6ryUM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_Jr0_Gr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4j6r 4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUAVWUtwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwCY1x0262kKe7AKxVWU AVWUtwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14 v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkG c2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4U MIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JU6v38UUU UU= X-CM-SenderInfo: pshqw1xhqjqxpvfd2hldfou0/ Content-Type: text/plain; charset="utf-8" port_init() parses the port channel number into an int, formats it into a small fixed string buffer, and later passes it to htons() for bind(). Out-of-range values can therefore overflow the local device-name buffer and still get silently truncated at the socket layer. Reject port numbers that do not fit in the 16-bit TCP/UDP port range. Signed-off-by: Pengpeng Hou --- arch/um/drivers/port_user.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/um/drivers/port_user.c b/arch/um/drivers/port_user.c index 3c62ae81df62..b3d393811d69 100644 --- a/arch/um/drivers/port_user.c +++ b/arch/um/drivers/port_user.c @@ -19,7 +19,7 @@ struct port_chan { int raw; struct termios tt; void *kernel_data; - char dev[sizeof("32768\0")]; + char dev[sizeof("65535")]; }; =20 static void *port_init(char *str, int device, const struct chan_opts *opts) @@ -27,6 +27,7 @@ static void *port_init(char *str, int device, const struc= t chan_opts *opts) struct port_chan *data; void *kern_data; char *end; + unsigned long parsed_port; int port; =20 if (*str !=3D ':') { @@ -35,12 +36,13 @@ static void *port_init(char *str, int device, const str= uct chan_opts *opts) return NULL; } str++; - port =3D strtoul(str, &end, 0); - if ((*end !=3D '\0') || (end =3D=3D str)) { + parsed_port =3D strtoul(str, &end, 0); + if ((*end !=3D '\0') || end =3D=3D str || parsed_port > 65535) { printk(UM_KERN_ERR "port_init : couldn't parse port '%s'\n", str); return NULL; } + port =3D parsed_port; =20 kern_data =3D port_data(port); if (kern_data =3D=3D NULL) --=20 2.50.1 (Apple Git-155)