From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 DBC0E43C061 for ; Thu, 4 Jun 2026 14:13:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780582394; cv=none; b=ZJO/kQcEI8Ac6GEv+Z+8mTBtWkfAUhgg4D+VGXvU+1e/9Rdb8JgAgGtKJzKZAclZehwpOtRbWeH9csEMVr9Zp+Jd/HVaLV0Jk6p4IdRjMZ+gxQ+mpd7XyLfi7WHjGvIqsTJIM+pcVtJOiIXxFVTB34c4FAZEGDjWpo4TPG825mA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780582394; c=relaxed/simple; bh=rlwz4rDaorvqYTObeylNlXMGxZ3xn6G5OMicLXRqugY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ecADRoj+tlTgJZtG3UB37xzn1/1pgTyQ94IP3ALOsHrbVEn4F/nRuGI0l9Fx5H0MhoVDVx/OAYGvrR8NcR4vloc1xcKPQD+n6A1qiWvGTYsGlJQT6a5ztCyb82629++21N/Mh+KuciKDIAZVrasQesm8rT69FwI94S386REPKbo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ci+WFpfe; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ci+WFpfe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0EAD21F00893; Thu, 4 Jun 2026 14:13:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780582393; bh=8PwqBX0IceUQbzAJv4wzvBtODRkrrNpAJz8gyBc59vM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Ci+WFpfeS4x0zsJXNdb9k1l12KQxvEpUqFdUOLSP6C+vkpRX5Hn2MSyZ0A2ck4Cw1 6BIIf9cIzSwwQ0Yua1Tgx0pNc/tvAa68B9zbFPmovQFveitTN/t/qhXgO+xUY97VTA t4ruXBur8PolEE8MxUjrBgbg0P3TVImryznQpBRpoDkKPSC7DsAjrOi03McpYpGGO4 fglpKKL+q15WcT2nPSjXXfPkE/rOxNVJSntDePoLP7o1JFbJlMl1lERpQLGb26AgPg IUGaHZjKQ5Tzm37TPbQjLlwDAFRdzyiCgc9zfUPxsFfKN9br38wJtbIb+fxYNimyH+ J1Htjk/Mpn12g== From: Sasha Levin To: stable@vger.kernel.org Cc: Johan Hovold , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 6.6.y] USB: serial: cypress_m8: fix memory corruption with small endpoint Date: Thu, 4 Jun 2026 10:13:11 -0400 Message-ID: <20260604141311.3549793-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026060437-pampers-nutrient-e02f@gregkh> References: <2026060437-pampers-nutrient-e02f@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Johan Hovold [ Upstream commit e1a9d791fd66ab2431b9e6f6f835823809869047 ] Make sure that the interrupt-out endpoint max packet size is at least eight bytes to avoid user-controlled slab corruption or NULL-pointer dereference should a malicious device report a smaller size. Fixes: 3416eaa1f8f8 ("USB: cypress_m8: Packet format is separate from characteristic size") Cc: stable@vger.kernel.org # 2.6.26 Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold Signed-off-by: Sasha Levin --- drivers/usb/serial/cypress_m8.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c index 1e0c028c5ec95f..e766b78f88634e 100644 --- a/drivers/usb/serial/cypress_m8.c +++ b/drivers/usb/serial/cypress_m8.c @@ -448,6 +448,14 @@ static int cypress_generic_port_probe(struct usb_serial_port *port) return -ENODEV; } + /* + * The buffer must be large enough for the one or two-byte header (and + * following data), but assume anything smaller than eight bytes is + * broken. + */ + if (port->interrupt_out_size < 8) + return -EINVAL; + priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL); if (!priv) return -ENOMEM; -- 2.53.0