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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E997DCCA471 for ; Fri, 3 Oct 2025 16:54:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 494938E0010; Fri, 3 Oct 2025 12:54:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 443E08E0005; Fri, 3 Oct 2025 12:54:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 333438E0010; Fri, 3 Oct 2025 12:54:10 -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 1DFB68E0005 for ; Fri, 3 Oct 2025 12:54:10 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id AE11C1A083B for ; Fri, 3 Oct 2025 16:54:09 +0000 (UTC) X-FDA: 83957400618.17.DE5D1B2 Received: from fout-a5-smtp.messagingengine.com (fout-a5-smtp.messagingengine.com [103.168.172.148]) by imf23.hostedemail.com (Postfix) with ESMTP id B8FBE14000B for ; Fri, 3 Oct 2025 16:54:07 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=shutemov.name header.s=fm3 header.b="V rCAewW"; dkim=pass header.d=messagingengine.com header.s=fm2 header.b=HJbP2dU1; spf=pass (imf23.hostedemail.com: domain of kirill@shutemov.name designates 103.168.172.148 as permitted sender) smtp.mailfrom=kirill@shutemov.name; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1759510447; 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=UB3IKnHmzh/QmKgOFKGx8BLdmDHf57NxnecnD+p+sRM=; b=bEzAovo/9CehxqqDBgbDsAmVeVb+lHGm6s20YTY+A8sQerKXujTDX4OuEyHcAoBd4ucUnI YNpseZ68CCgtCL2HgaF6Ss4x+iTWSus1Ty04S3cvPI/WqvfAynnwO55VktELX+wc/aPGc0 v583GYhfWcnfRfdmEwyVcGpTcCAzcfQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1759510447; a=rsa-sha256; cv=none; b=qdM60oXaExvzJxcurQFtJkAogJz6EphcafOaY0O3+TvtSbzwXFcqA4ibA5bmtvOccbSG2D g3fYb4UABxjRtjTPZk6vqvJANv4p2fHBVOJbCLzlra4Pcf0DfUO6cVGv2xfQm+M39wCW6N BNvm9TNDjLy3RJM08iqorsdsUMUfDIk= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=shutemov.name header.s=fm3 header.b="V rCAewW"; dkim=pass header.d=messagingengine.com header.s=fm2 header.b=HJbP2dU1; spf=pass (imf23.hostedemail.com: domain of kirill@shutemov.name designates 103.168.172.148 as permitted sender) smtp.mailfrom=kirill@shutemov.name; dmarc=none Received: from phl-compute-05.internal (phl-compute-05.internal [10.202.2.45]) by mailfout.phl.internal (Postfix) with ESMTP id 12A22EC0278; Fri, 3 Oct 2025 12:54:07 -0400 (EDT) Received: from phl-mailfrontend-02 ([10.202.2.163]) by phl-compute-05.internal (MEProxy); Fri, 03 Oct 2025 12:54:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov.name; h=cc:cc:content-type:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:subject:subject:to:to; s=fm3; t=1759510447; x= 1759596847; bh=UB3IKnHmzh/QmKgOFKGx8BLdmDHf57NxnecnD+p+sRM=; b=V rCAewWI7sbJvCIV/zpcnz6A0CPYZVWfFX0Dtm6UVGY6RT/28Zy15ntNNBSsAtIPl 4AeS0Pk+Ho+rYuDaaB5Hw8Klh46ivi7sHEvbAweBb3JCb/miDh0XneQcuqst6+iP DHK0uh+ii8tWQ/XnmCSykrps7XG21DgZeTLz9ukgJ1iOPBrHGnVuXlbxVeSYLsbZ cL13AnQ6Yg47zxCMlkQh0NMH4W2OUmvwFnwM0klqG7+4HdB4gezArrTeuYAxGz7V ME2GJ/yA/ViRO3iBOMsBiX8P2RbCtCRrrX2Qx4yOchMwc9QS9uxG0tWIxDzVxn0Q O8zpttlCxiJljP2WsmAzQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:subject:subject:to :to:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t= 1759510447; x=1759596847; bh=UB3IKnHmzh/QmKgOFKGx8BLdmDHf57Nxnec nD+p+sRM=; b=HJbP2dU1gXqvJr5xZP81JrdPktlFylwZz2QyJKBRAemfB/Na89d 4uMVsS2+JGsNIkxPYS3qPWpObEW7BZQXNk4si7jgrgb9bykcr+01O03QRuqBfSJk CKQ8zCWLG+5Y2L+/ZLXa7Le/UG2trAbGxDTUfJWUGjohNBewZmIkyf2BCHIxtdXh 0ANiyZFPCCOwowLLBasMsHF8QE2PFo2kMVAU56I/zlJiufJMFrFy6TFIrjofQ7Ut 6RU6mi1hsO08c8503/6rxQumSpu9sifWbOGYmYQkn1ixDCM91gcAXS8PGP13xoNz BqTB4K8OU8Q1vL3G52i84bNpPZ/X7E70A7Q== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtdeggdekleegfecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpuffrtefokffrpgfnqfghnecuuegr ihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjug hrpeffhffvvefukfhfgggtuggjsehttdfstddttddvnecuhfhrohhmpefmihhrhihlucfu hhhuthhsvghmrghuuceokhhirhhilhhlsehshhhuthgvmhhovhdrnhgrmhgvqeenucggtf frrghtthgvrhhnpeegfeehleevvdetffeluefftdffledvgfetheegieevtefgfefhieej heevkeeigeenucffohhmrghinhepkhgvrhhnvghlrdhorhhgnecuvehluhhsthgvrhfuih iivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepkhhirhhilhhlsehshhhuthgvmhho vhdrnhgrmhgvpdhnsggprhgtphhtthhopedviedpmhhouggvpehsmhhtphhouhhtpdhrtg hpthhtoheprhihrghnrdhrohgsvghrthhssegrrhhmrdgtohhmpdhrtghpthhtoheprghk phhmsehlihhnuhigqdhfohhunhgurghtihhonhdrohhrghdprhgtphhtthhopegurghvih gusehrvgguhhgrthdrtghomhdprhgtphhtthhopehlohhrvghniihordhsthhorghkvghs sehorhgrtghlvgdrtghomhdprhgtphhtthhopehlihgrmhdrhhhofihlvghtthesohhrrg gtlhgvrdgtohhmpdhrtghpthhtohepvhgsrggskhgrsehsuhhsvgdrtgiipdhrtghpthht oheprhhpphhtsehkvghrnhgvlhdrohhrghdprhgtphhtthhopehsuhhrvghnsgesghhooh hglhgvrdgtohhmpdhrtghpthhtohepmhhhohgtkhhosehsuhhsvgdrtghomh X-ME-Proxy: Feedback-ID: ie3994620:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 3 Oct 2025 12:54:05 -0400 (EDT) Date: Fri, 3 Oct 2025 17:54:03 +0100 From: Kiryl Shutsemau To: Ryan Roberts Cc: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Amir Goldstein , linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v1] fsnotify: Pass correct offset to fsnotify_mmap_perm() Message-ID: References: <20251003155238.2147410-1-ryan.roberts@arm.com> <76cd6212-c85f-4337-99cf-67824c3abee7@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <76cd6212-c85f-4337-99cf-67824c3abee7@arm.com> X-Stat-Signature: 3q9o1gd9ss6fnk9ysurojfeygxyrudia X-Rspamd-Queue-Id: B8FBE14000B X-Rspam-User: X-Rspamd-Server: rspam03 X-HE-Tag: 1759510447-269891 X-HE-Meta: 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 LFLsMH/z dfqSmPzQCc0qdbk2TYkATTvY2tGNrelALMr6UD/6BgEbRBRBvxBH+MJc4IGhtJuqKfQyyOaf4htzZ85QIkstUXoVb73NaLwuDo2Yq5Ie5Kjlzch+APWt65+RRGbYR6EPboY5OhO6fgdkQRGGu19+d4jA87YgqmF1T64/yw3cJ0oUkNIvb0gclnYS4YlMed4mPPcksK8ECLe/ECavCCQLXk3spr+HUEYBxzgfitylRB/RgMUENSkqXMGfii6AuieNleCPWdG3EZ9vcG/h+fJ8jG2RK41JdDmhLBJ4x0omK4iHS1MPbzTRplkjmVWhkmkoj+npvIpzXsQzfE4fyFEiYgDi4kRxYHY6B5731NkmwtTki/v169N7SgUHe+iSS1LmvsVdRQ0hfJxkwH8qSkiuKTcksgjWD+Z/05LnsrrncS8V7hUF26QsqUYUMyg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, 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 Fri, Oct 03, 2025 at 05:36:23PM +0100, Ryan Roberts wrote: > On 03/10/2025 17:00, Kiryl Shutsemau wrote: > > On Fri, Oct 03, 2025 at 04:52:36PM +0100, Ryan Roberts wrote: > >> fsnotify_mmap_perm() requires a byte offset for the file about to be > >> mmap'ed. But it is called from vm_mmap_pgoff(), which has a page offset. > >> Previously the conversion was done incorrectly so let's fix it, being > >> careful not to overflow on 32-bit platforms. > >> > >> Discovered during code review. > > > > Heh. Just submitted fix for the same issue: > > > > https://lore.kernel.org/all/20251003155804.1571242-1-kirill@shutemov.name/T/#u > > > > Ha... great minds... > > I notice that for your version you're just doing "pgoff << PAGE_SHIFT" without > casting pgoff. > > I'm not sure if that is safe? > > pgoff is unsigned long (so 32 bits on 32 bit systems). loff_t is unsigned long > long (so always 64 bits). So is it possible that you shift off the end of 32 > bits and lose those bits without a cast to loff_t first? > > TBH my knowledge of the exact rules is shaky... I think you are right. Missing cast in my patch might be problematic on 32-bit machines. Reviewed-by: Kiryl Shutsemau -- Kiryl Shutsemau / Kirill A. Shutemov