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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 27410CDB46F for ; Tue, 23 Jun 2026 12:19:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=okApS8kA1BHmpX9NtGOiC0KXJACuDAVb6ZoT6zw+Ygs=; b=uasZFXiu9ryveZATanxa6e4D+x WHjoPmqHUu35+3/mtw0LnnJSUeaWwaiX1bTqVMtADkxFEJG/cPfWtOkXHQIhv2U0z+IA+7k9UUycy GtdOVbsvlHD5/en4KBpSuhCTVtbTgHwmQd06fAf1Q4SiltW4zzUnx83UZ6oD5Y/iP64pbpLnB12F0 H1vnYs09mjg7dCpGjf2+gCdxaGCy/CNTHBNRZQFaMU2iqKf0w8irlWrFU0ALsZh39kkELjjIv5Ssb X7+lvlI4mkIpAI4wWcd1tc5NXWLYIqusx0OuW/58BnNppNTP8riWoWm8TuHakRaXE2kLu9gwbfT3Z XYlvEJGw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wc05z-00000006FQV-2kJ5; Tue, 23 Jun 2026 12:19:15 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wc05y-00000006FPy-3Ybv for kexec@lists.infradead.org; Tue, 23 Jun 2026 12:19:14 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 9B0294373A; Tue, 23 Jun 2026 12:19:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 145E61F000E9; Tue, 23 Jun 2026 12:19:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782217154; bh=okApS8kA1BHmpX9NtGOiC0KXJACuDAVb6ZoT6zw+Ygs=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=m2knUe1M/njq7jjIqMM0aYd0IQ1XadhqQ4jHEZXlizp3dwr2PJ2e3+wjZ0In7VD6r +/Pkf7DTaEef2gEGsEyTvnu1KWETnlSwseXzQ0BP6nB7fOkEZ0SwRdHibAG9V3aLz2 xFqh4wBNAyd/83J23xxCJTz6i06Xw7goDbYaJT8QMTkdJ5XPeVBWESgp3K0viBLkPs V30JcTeKkiT7nLtPEaHhjNVQGN/g9YjHKPZxpfJ4VxEiWx7GcEQQ8rtaegWUBuNW7l N+9jFDja10LrcQIoov0l7Vbv4xErtjZ11aJ7GMV9bJefR1ifZ3PmI3k7E5MWLp5cge wzrxfxhdONdbw== From: Pratyush Yadav To: Tarun Sahu Cc: Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Andrew Morton , Alexander Graf , kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 1/3] mm/memfd_luo: validate serialized_data before conversion In-Reply-To: <20260623105201.3724592-2-tarunsahu@google.com> (Tarun Sahu's message of "Tue, 23 Jun 2026 10:51:59 +0000") References: <20260623105201.3724592-1-tarunsahu@google.com> <20260623105201.3724592-2-tarunsahu@google.com> Date: Tue, 23 Jun 2026 14:19:11 +0200 Message-ID: <2vxz5x39o3eo.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On Tue, Jun 23 2026, Tarun Sahu wrote: > In memfd_luo_finish() and memfd_luo_retrieve(), phys_to_virt() was called > on args->serialized_data before checking if the physical address is valid. > Since physical address 0 does not map to virtual NULL (due to direct > mapping offsets), the subsequent check 'if (!ser)' was ineffective at > catching a missing serialized_data, leading to unsafe dereferences later. > > Validate that args->serialized_data is non-zero before calling > phys_to_virt(). > > Fixes: b3749f174d68 ("mm: memfd_luo: allow preserving memfd") > Signed-off-by: Tarun Sahu Reviewed-by: Pratyush Yadav (Google) [...] -- Regards, Pratyush Yadav