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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7958AC6FD1F for ; Thu, 21 Mar 2024 17:05:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 16D5C6B00C5; Thu, 21 Mar 2024 13:05:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 11F6D6B00C6; Thu, 21 Mar 2024 13:05:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F284D6B00C7; Thu, 21 Mar 2024 13:05:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id E32316B00C5 for ; Thu, 21 Mar 2024 13:05:07 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id B42D9A2075 for ; Thu, 21 Mar 2024 17:05:07 +0000 (UTC) X-FDA: 81921671454.25.6412E83 Received: from mail-pf1-f181.google.com (mail-pf1-f181.google.com [209.85.210.181]) by imf27.hostedemail.com (Postfix) with ESMTP id B540D4001A for ; Thu, 21 Mar 2024 17:05:04 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=AcrCP5GC; dmarc=pass (policy=none) header.from=chromium.org; spf=pass (imf27.hostedemail.com: domain of keescook@chromium.org designates 209.85.210.181 as permitted sender) smtp.mailfrom=keescook@chromium.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1711040704; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=abV1KSQfMj1DzU4Wxs3gXedK8VwaffSMAGzyZA+mQ48=; b=DNKmI9YlDCl3a8OrAXWIQqs7xYhKF+V9niozjRDpIGaQDWCIDxGHz2xuWaHBvrCd7NDeZT exoozgqmhohjmeWwiSUN9KzbpzrD9D+ZMlsdJGd4woMQihYj6EFJj7g56yjAcKya5RN4VC TGS3wZInMxiAzrYHhJKPRzyuS+u0wvM= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=AcrCP5GC; dmarc=pass (policy=none) header.from=chromium.org; spf=pass (imf27.hostedemail.com: domain of keescook@chromium.org designates 209.85.210.181 as permitted sender) smtp.mailfrom=keescook@chromium.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1711040704; a=rsa-sha256; cv=none; b=gv+l1Z2kQkmt+Y1RwunD1LGsmCyFXtAfE/soMIrZpVhw9gWBi7hFXVUWINHMoEA7rVt68w oPsMPoxy4a/zU+CicfgcbuYp54DkD1CmqqqCA3teUvfZE1QvBEfLr/Uyc0uSRyteSJhJHW 6q0PZuhv07+0swLozbQptcJCqI7jX1s= Received: by mail-pf1-f181.google.com with SMTP id d2e1a72fcca58-6e6ee9e3cffso805868b3a.1 for ; Thu, 21 Mar 2024 10:05:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1711040703; x=1711645503; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=abV1KSQfMj1DzU4Wxs3gXedK8VwaffSMAGzyZA+mQ48=; b=AcrCP5GCpgj+F6iPgBmWsBSMgacfvVLRajTXrQtVFnp022QyQFTxL30ZDVVSWVPiuD Ew/FGUMrsqPFcOA6DLpZWAsKMIuoUgEXwGwhjsbuI06jZy0+y9II5FQTiiyC/O0sHlR9 ChfKVzxZxGsFHUaOVEF7vZlSrtPqRur1mWYdY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711040703; x=1711645503; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=abV1KSQfMj1DzU4Wxs3gXedK8VwaffSMAGzyZA+mQ48=; b=holGwmxmcx+uHYV4eVda0q83cEKtEqH22gRz3YumrPrQ8Xcs1n/QSb/NRUy5TFv0Hr pfIPYo0syzFj9HuTbdbqVkGJUDGUG8nXPA9y4vg/HoHXMzb8h5ob/Iolq7iKcI76pPJE H5DaQG8HpW1acHIAisvkA/9CYB291rLj/yNjtLWgwTPKSNkfuFIQgjNFf+/XCVvKj4B4 vFzG+DD3AvHhKsT7J+tONnplnB4HMUBHfNPwihTRaiQ9h/DnVpN5Xan2WzixIuCoerzo bIpXrjFGRMCsQ7UAZFET1sMY2RxBgrYkDT/kvIpISFIlRxOgxUFfx7rq+Ydq2rqBApwq RYGg== X-Forwarded-Encrypted: i=1; AJvYcCVC7UEkrsMofoDR5GLnG3M7UesVJRQtCyQg2InYxsUvmW30ziLZP3Hj6uLAsfbNaECu6K9jh09EJYpngdl28sXVt2k= X-Gm-Message-State: AOJu0Yzj8jzcfecXqUAmnP1E8TI66iR7kOvxemoJU+hCge81TXPXlQ+V E6U9qq6eT3WSy1Y8ND9aucbRykdywnGCW3KKvssRZ6vTJ03dqOGn1qR8WZOW9A== X-Google-Smtp-Source: AGHT+IHjXoA11dA50WtbnjUSI44eAM2tLeRUNZtkfUInXbO/jmancQD+KVgSdBcSUYmuk5/U/6YV+A== X-Received: by 2002:a05:6a00:3a05:b0:6e6:5291:1779 with SMTP id fj5-20020a056a003a0500b006e652911779mr4275257pfb.6.1711040703382; Thu, 21 Mar 2024 10:05:03 -0700 (PDT) Received: from www.outflux.net ([198.0.35.241]) by smtp.gmail.com with ESMTPSA id t16-20020a62d150000000b006e731b44241sm73573pfl.42.2024.03.21.10.05.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 Mar 2024 10:05:02 -0700 (PDT) Date: Thu, 21 Mar 2024 10:05:02 -0700 From: Kees Cook To: Max Filippov Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Eric Biederman , Alexander Viro , Christian Brauner , Jan Kara , Rich Felker , stable@vger.kernel.org Subject: Re: [PATCH] exec: fix linux_binprm::exec in transfer_args_to_stack() Message-ID: <202403211004.19F5EE27F@keescook> References: <20240320182607.1472887-1-jcmvbkbc@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240320182607.1472887-1-jcmvbkbc@gmail.com> X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: B540D4001A X-Stat-Signature: 48yceery1r6pb6ahx9we4fhnjhaow4sd X-Rspam-User: X-HE-Tag: 1711040704-96481 X-HE-Meta: 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 Gk0OJIBs B1cdkJGE4L1tI8lWL/QF6erZi9SeAaBPKUT6GeIeil4bTOtjwUV6uglhLembBXXEdf7P5mSbtUj7SlifS/djwr2HfdciUgV2WKHeDYUKKmTLYYgSHgSqHVfmqsGGu9wKRQsMToEMiAu6P7IG10mu5SGcmaGAFYzt17/TjK6PaLYD7Z7x4HHdHkyNa6ULBSak3n0aJDTQIriVb8HbkWWsqpON3o+yzgbMuVzmxTkEeke/JMzQlhQ8++Uk6Z9tcEPGtPeB+pwTo0bH8553PQzumEjDaP0Dez7O3LipIQmmZqW6sEC83MyiflPNMLeZNcCH1zv/CWVcehHmqAXTKzO6I7w9ZZuXc9uWGvCKkVK0PZaxFFMZ5H3E/Jn0pkoIz5W1NVZU3ZFUpOWSq4b/XITUf3qXgmhP9k6oj56S6V6tJc2P+taMpwb1uksRE4hmPm5Lb2wjCNiQlR/oNsBEUdOcpgXlusZVfcKOFN6dq X-Bogosity: Ham, tests=bogofilter, spamicity=0.000039, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Mar 20, 2024 at 11:26:07AM -0700, Max Filippov wrote: > In NUMMU kernel the value of linux_binprm::p is the offset inside the > temporary program arguments array maintained in separate pages in the > linux_binprm::page. linux_binprm::exec being a copy of linux_binprm::p > thus must be adjusted when that array is copied to the user stack. > Without that adjustment the value passed by the NOMMU kernel to the ELF > program in the AT_EXECFN entry of the aux array doesn't make any sense > and it may break programs that try to access memory pointed to by that > entry. > > Adjust linux_binprm::exec before the successful return from the > transfer_args_to_stack(). What's the best way to test this? (Is there a qemu setup I can use to see the before/after of AT_EXECFN?) How did you encounter the problem? > > Cc: stable@vger.kernel.org > Signed-off-by: Max Filippov > --- > fs/exec.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/fs/exec.c b/fs/exec.c > index af4fbb61cd53..5ee2545c3e18 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -895,6 +895,7 @@ int transfer_args_to_stack(struct linux_binprm *bprm, > goto out; > } > > + bprm->exec += *sp_location - MAX_ARG_PAGES * PAGE_SIZE; > *sp_location = sp; > > out: > -- > 2.39.2 > -- Kees Cook