From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-vk1-f171.google.com (mail-vk1-f171.google.com [209.85.221.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 19DCC381E9D for ; Thu, 3 Sep 2026 04:25:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788409507; cv=none; b=QV4CaK9hRDxKnC1+USSf/t6V1zFmq6n8KvSp1QNzXTYbzcv2cOxVbdF34mqICufvD+PdTT//Iw2DnCld+HsqmJKZGJBKVzriMyaOWIxs28v08uD18SZU11a5zYPbuEK9UH+npWkOCU9YuB18MDFMANae1jGApSnMDG5JiJBfGXo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788409507; c=relaxed/simple; bh=Pm2g6WlUGa7uN5+D5OLV6Tnth8Vjj/o0THldBmej17c=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=rdcqL+U0xyzv26oXDn3xpFU9A/cqrS47F+LC4ayg88u4LcENuOAO1TwH8C/FOaz8yvqv5k2/5YuxIdb0OHdsO1GcGvp5osdOmJzw2K4SwQq2sjCMHoerTRvkPO3DsI78ROUVT3rGsUI3syAY5rTnx2tAm8lau8sLlYvtDGG6u+M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=ETemhVRK; arc=none smtp.client-ip=209.85.221.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ETemhVRK" Received: by mail-vk1-f171.google.com with SMTP id 71dfb90a1353d-5bfaa014978so1097995e0c.3 for ; Wed, 02 Sep 2026 21:25:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1788409503; x=1789014303; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=UwJ9Kyc3h7M9fN4mjn/dwpP9OV7iadH7CHAovsxH2MU=; b=ETemhVRKX/V7r5NllUfDLLX7w1KiOfbd5NmKV+VufArPHXjk5gNZgWJnYNZyIPta92 +LWVfTj7H2Rr3WbISdiL2cRtcs9e5Gel+gQMGl3Dcwb+oElWHr0zs9TOC0mIhyqeWzZd 8sdSBgH1Xm9ChYzg/j5Dj27akxdC8gMatdCWKQiS2CZW+NTVpO1jop5uOiYBei+yyAUy 17WGGUZVFFhMah1UUGbYs3v4TBjrIQKrRJSkzPvdjLaOUbeNs2gFHKjFXBu5j440izMt 7AQ3nxApu3mmuG5Zza9+2OskE0rtvONVdmo46Ove/Eq9JxQ7ofGeQW+8rbWJof63MB2Q vSyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788409503; x=1789014303; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=UwJ9Kyc3h7M9fN4mjn/dwpP9OV7iadH7CHAovsxH2MU=; b=iTFzGQTvsoiVny9FDCIB7305y4I14JtdeHm2KEyHhx7C+MxgVHdjQzggz5HCbXPFa4 c93Y0hpPYCZ75GYWmk+f0AGmaUfKWk3kfFU8w5KLs4rEKn1TtYEjh1/ciymm8Kdh3JCa ovwFNJgcgoGMsY3hugerKNTFXX/D4k8Mw3GschTJIUawKyI3W5no4LpbrxdB4TqVZ6lk XlPz8Ak0uVs8VDFIchXg7SnB9znbYnCBODPSF9W0tkuVWgsm/3M6qHSYmWsxsTJotiWT iZ9rptfJ64hRZfFOkZdWenCCpJ0T3Hm66pZusCr5Sb343V034btDpVKUJIBpqzWxaK4a PUXg== X-Forwarded-Encrypted: i=1; AKwUvBy7q/B6hhi+tn/KdP7clqq8XAallyNy7QzXKxvF/3r87ou1xURCqFNm1W0TjjkUBuMu5O/6fUqq1R5uJw0=@vger.kernel.org X-Gm-Message-State: AFuF++l3c2F76WDXIDGZtcItqcPWnONdRGdAMx6+ms4yYGJdyGt5jcGZ /uiLGzt0vMqomOMI6n87z+vxfUS2YdNxWcyY0Xg9b5XTFWB2FLdiitKX X-Gm-Gg: AYBFou1/PGI8N+6pdKpiGr2KqqA1gYX7E8US+/d7oodMla+mwbneFhkcEi8bL1Iof+b gUlojPGwrm4v8l0KylZ+pwXTJ97P4fKc/KDb0epGWtXM/nuOQLw+YdCNGAqh15AlOaVEheRSdKQ ZfT3AXZNXHIBnUpDKu3diItfRp7FDwQ7wYl+KYVUz9XcHQ0jsA0RwKsAy697cpFLZ+gx5YLon4V TGFE4f98/xfp4Qcpc+f9qiUVwgyyuU369hxmjvIgPEA+ABDd5f+6htXg4is9cWVyXSGQUuVED1O j7apIqxtID+7X1pDB1r2rZFJEPlLGPPa8c23vBM2/aj096RUDguVBpAhIpQks76pvo1zFdramjE ASa78F+dQKRDItDIT5tG60HhCBxTF1w2I63ix2H88N4kkjKGpBl7aaX4QtsxorBCAUPdihL5ICD 6o9Z7Pb36Qm4PcGLZC/zubLyXeNF1BgUv4aRjuu0UEg9Kaqh8q0KKZ X-Received: by 2002:a05:6102:f11:b0:789:3f43:645b with SMTP id ada2fe7eead31-78a1f12285bmr3209154137.2.1788409503017; Wed, 02 Sep 2026 21:25:03 -0700 (PDT) Received: from adriano ([190.215.95.120]) by smtp.gmail.com with ESMTPSA id ada2fe7eead31-78a1a4b1143sm3857241137.7.2026.09.02.21.25.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Sep 2026 21:25:02 -0700 (PDT) From: Adriano Cordova To: gregkh@linuxfoundation.org Cc: johan@kernel.org, jirislaby@kernel.org, linux-usb@vger.kernel.org, linux-serial@vger.kernel.org, Adriano Cordova , syzbot+473d7477c523b41d4046@syzkaller.appspotmail.com Subject: [PATCH v2 0/2] tty: fix break race Date: Thu, 3 Sep 2026 00:24:27 -0400 Message-ID: <20260903042429.130320-1-adrianox@gmail.com> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit A timed break (TCSBRK/TCSBRKP) and the unconditional TIOCSBRK/TIOCCBRK can race against USB disconnect and call break_ctl() after the device is gone, dereferencing freed port data in keyspan_break_ctl(). Both patches are needed: the tty core must not issue break_ctl() to a hung-up tty, and serial_break() must not call the driver after disconnect. This is the same two-layer protection read and write already use. Changes since v1: - v1 https://lore.kernel.org/stable/20260903022452.111316-2-adrianox@gmail.com/T/#t - Proper check on the tty side, plus check on the USB side. - Tested syzbot Reported-by: syzbot+473d7477c523b41d4046@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=473d7477c523b41d4046 Tested-by: syzbot+473d7477c523b41d4046@syzkaller.appspotmail.com Adriano Cordova (2): USB: serial: fix break_ctl() NULL-pointer dereference tty: fix break race drivers/tty/tty_io.c | 19 +++++++++++++++---- drivers/usb/serial/usb-serial.c | 3 +++ 2 files changed, 18 insertions(+), 4 deletions(-) -- 2.51.0