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 F2FB0606A31B for ; Thu, 5 Nov 2026 20:51:15 +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=Omt+m9Pg; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=P/lqti2w 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=XJ6642CpUbmT9faJdQPyT1x7rBQwlIa8jLjslbId/hM=; b=Omt+m9PgtrSPHF1KPSj4ByEldB lZ4hOV1Up1YpoYxywufi8kX+YTZzQfcSPdB6UKl7/KKtnhb/f9I6I0rav6TX/aL4IyNd5Y1FzWhTR EfWhyZvsMPL7FqZDgvZ/6+tskwK43YkqokSyVZO07+Q/0nt7HWxhG0aYxcum05i6fFJfb8woA8R3i VHWMZDWSz7hGmUJAhj7yhXQwZsk00EqneN8NLcgGfYgc4aCF0Hn/C7yeoLxYYvaRkhll+RRo1qLAO aqZjoxifroDM67rDzbLtkCCLM/6DqvvYvLe7vYGWIfskrPiTB0ty4WbpKHw9UNoe/6KPW+HyrR9Lv Laycz/5Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xP3Cq-0000000AM2v-0reh; Thu, 05 Nov 2026 19:33:04 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xP3AJ-0000000AKnN-2rsf for kexec@lists.infradead.org; Thu, 05 Nov 2026 19:30:40 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 25162601C1; Thu, 5 Nov 2026 19:30:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6041A1F00A16; Thu, 5 Nov 2026 19:30:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793907026; bh=XJ6642CpUbmT9faJdQPyT1x7rBQwlIa8jLjslbId/hM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=P/lqti2w1OrQg4Z7Rh1XUrJV0Rjz7sHRa7GeKVhzsOuNNsupbAfab6BhPFMbRRQ6s R8j5pjl35ymm8jhjHHKcL2Q4aHubkU8vyNWYsO5AmMbS2QDOO/DgRHsMLNj9TrxKe1 RLG6VHdhILTSjc66At8B4CNW4ugXE4mn1IgKnc09t9nIGlKrJzpXyj9W12pQoosTgz Ui8sy5shZnv8JDmiwBsQgNMlMgNj3iPBOTCVS4CXbwShJnC18KKd0G7+F0OW8ooQud 39xpw8p1V6y27YXqhAEZFOk06bAwJKDYaY5zNC7nznc8A+Y2K4mOb6/4TJKIimOEX3 Yxvmf/b2YoZBw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH RESEND v2 47/51] 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: <20261104-work-procfs-bugfixes-v2-47-021c84d852e0@kernel.org> References: <20261104-work-procfs-bugfixes-v2-0-021c84d852e0@kernel.org> <20261104-work-procfs-bugfixes-v2-47-021c84d852e0@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 05 Nov 2026 19:30:25 +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/20261104-work-procf= s-bugfixes-v2-0-021c84d852e0@kernel.org?part=3D47