From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AD8D7606D819 for ; Tue, 3 Nov 2026 14:48:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=tASqvW2d; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Y7X/3tby DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Reply-To:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Date: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Cc:To:Subject: From:Message-ID:MIME-Version:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=w2/IP9Nbbwaq1rM5X5TI+Z6uMBVhleLl4dqv4RtKuWA=; b=tASqvW2dGcTsDVTYAJql9L095l veT+KBT+zNZ5JXF8OLpFHC7IZKbAvfCq6WbkcA4mMT9dwg8a3SVUUMSx4RKO5o5HDfm39XAP7N+nS u8kp1+KPn0NHe3hcHerLwNqz0+Uhe3v9R/bzKIosXB3Kkwz+WnhUXosdhOVFyufDW7OK9ivvnRMTv MJLFgcErAXOzSc/zWPQDFUKF/JIHXCfNhup0wWyRA/3RXOSe66c/SCrUIAYQ5s3qXtFdSprrjzfRG PCdDUtuJ15YaQHMeFBRbnDL9GP4sDeGO3Zi15YTy+h+qMZ52on4aP75FnR8JGR0oBvFk7TaJtX4EQ uwx4zdBw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOFoe-00000002lxW-0wYq; Tue, 03 Nov 2026 14:48:48 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOFoU-00000002lns-2ttL for kexec@lists.infradead.org; Tue, 03 Nov 2026 14:48:43 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 6D12040220; Tue, 3 Nov 2026 14:48:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 62BCD1F000C1; Tue, 3 Nov 2026 14:48:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793717318; bh=w2/IP9Nbbwaq1rM5X5TI+Z6uMBVhleLl4dqv4RtKuWA=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Y7X/3tby5ok9JWnFEB65JWWmANthXkUjcXdb9uSdjW0JhmR9HZjv1YT00Y4DsNv+W Biuw8DvsjPcl772z7tONEXXEXtYepxE4vSjBigB6zSeMFdoUu1aYEPpOnorED4q8/6 jPTA+4fCMfDW09aVM/QBTydO81RE7CgVc1Pp6JLW4SpOJYkbo9BUyN8EiUCyyjZQlp kv0bhokpcFD78wxy4BaRRF0TZr/IYs/oBfNzPTLQzgQNoJpQ9WrZvetS4oHr4FTbxa gW0WNwcqv3NgJchB8vagqoYRJIHigOkbqStPD4Hh4/ge7N18B2zIy8QT5B5D4G6wz1 nY9eJEyDXdkew== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH RFC 34/38] proc: sysctl: look at the table under sysctl_lock when creating an inode To: "Christian Brauner" Cc: "Linus Torvalds" , "Jann Horn" , "Josef Bacik" , "Chris Mason" , "Jeff Layton" , NeilBrown , "Eric Dumazet" , "Thomas Gleixner" , "Al Viro" , "Jonathan Corbet" , "Christoph Hellwig" , "Greg Kroah-Hartman" , "Joel Granados" , "Kees Cook" , "Jan Kara" , "Jan Kara" , linux-s390@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-usb@vger.kernel.org, samba-technical@lists.samba.org, linux-m68k@lists.linux-m68k.org, linux-serial@vger.kernel.org, "Takashi Iwai" , linux-ext4@vger.kernel.org, "Chuck Lever" , tytso@mit.edu, "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" , "Christian Borntraeger" In-Reply-To: <20261102-work-procfs-bugfixes-v1-34-59422ed3e465@kernel.org> References: <20261102-work-procfs-bugfixes-v1-0-59422ed3e465@kernel.org> <20261102-work-procfs-bugfixes-v1-34-59422ed3e465@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 03 Nov 2026 14:48:36 +0000 X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Sender: "kexec" X-Spam-Status: No, score=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: > proc_sys_make_inode() checks under sysctl_lock that @head isn't being > unregistered, lets go of the lock, and then reads the mode of @table > and calls ->set_ownership() with @head. That's fine as long as the > caller holds @head in use, which keeps unregistering from getting past > that check. The next patch has a caller that only pins the memory of > @head. For that one the table, and whatever the owner of the header > keeps behind it, is only there for as long as nobody unregisters the > header, which happens under sysctl_lock. So read the mode and set the > ownership before letting go of the lock. The ->set_ownership() > callbacks only look up ids in a user namespace. >=20 > No functional changes. >=20 > Signed-off-by: Christian Brauner (Amutable) Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261102-work-procf= s-bugfixes-v1-0-59422ed3e465@kernel.org?part=3D34