From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B6C5C2D0E7 for ; Thu, 26 Mar 2020 23:27:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 247FE20774 for ; Thu, 26 Mar 2020 23:27:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585265248; bh=Y25GVBK9+D3VXi1+RSyrgN73g8LYhaxniIkwT/AEKxg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rdD3nHeeUJtGUsBcFVVmkkkDRNDtydXWHj3LTFbGOGKGr80lRFL6+/YPKy/YrENUv Dsb9HxpyPFeT+sHgUoviE1UX9+ARt6KgAR1HMWqoKbQs4cdtzpKFYzL2hPk7Fm1l/E iVwtsAMCqsvV521wN1Gn2eML7Fuudhj3xXWosKIY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728132AbgCZXY5 (ORCPT ); Thu, 26 Mar 2020 19:24:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:45136 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728005AbgCZXYx (ORCPT ); Thu, 26 Mar 2020 19:24:53 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B40DB21582; Thu, 26 Mar 2020 23:24:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585265092; bh=Y25GVBK9+D3VXi1+RSyrgN73g8LYhaxniIkwT/AEKxg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F3izkWvEgp+y8vcU4U8RC3xcJN6z/cmfFT1yIDwYf5tdr2mlYBUxYqDF5Ir2X+Z/N 0bPmVDwjq4Mp3e7fQrwTs24jVhGWOcg12FVFrvyvD7jr1J5ATmOfVZEraW2rwdk6M4 Xil/2ynVgZMTm9n1ILaknfEf16QDEHa/DssjxGNM= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Biggers , syzbot+8da9175e28eadcb203ce@syzkaller.appspotmail.com, Jiri Slaby , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH AUTOSEL 5.4 18/19] tty: fix compat TIOCGSERIAL leaking uninitialized memory Date: Thu, 26 Mar 2020 19:24:30 -0400 Message-Id: <20200326232431.7816-18-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200326232431.7816-1-sashal@kernel.org> References: <20200326232431.7816-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Biggers [ Upstream commit 17329563a97df3ba474eca5037c1336e46e14ff8 ] Commit 77654350306a ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()") changed the compat version of TIOCGSERIAL to start copying a whole 'serial_struct32' to userspace rather than individual fields, but failed to initialize all padding and fields -- namely the hole after the 'iomem_reg_shift' field, and the 'reserved' field. Fix this by initializing the struct to zero. [v2: use sizeof, and convert the adjacent line for consistency.] Reported-by: syzbot+8da9175e28eadcb203ce@syzkaller.appspotmail.com Fixes: 77654350306a ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()") Cc: # v4.20+ Signed-off-by: Eric Biggers Acked-by: Jiri Slaby Link: https://lore.kernel.org/r/20200224182044.234553-2-ebiggers@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/tty_io.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 802c1210558f2..d4c7f663efe99 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2731,7 +2731,9 @@ static int compat_tty_tiocgserial(struct tty_struct *tty, struct serial_struct32 v32; struct serial_struct v; int err; - memset(&v, 0, sizeof(struct serial_struct)); + + memset(&v, 0, sizeof(v)); + memset(&v32, 0, sizeof(v32)); if (!tty->ops->set_serial) return -ENOTTY; -- 2.20.1