From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793632913; b=GGfKPca+jsxsFZeKLAbrUl2PH7YuEcDFwp7FxtxuJQ4qJS+NccpghQpuz+f4w55PIkOg ebfp8JuCsnc10VzYb4NsWgdY9E9Mx6c4g4fMOunYiL6/syn1raOGm152yH0Pl5jTXcOBc EI+kLMVtjqTcqidBCt6C9aRqlRDLMY+COoQ9WMU9P2kotpb3MzwO33YhfIQZ5o2yRGD4c k9lsD8P56iKtZXMKyqt+w9WtJfHpc8XpXHt2wUXxN12lX7s2EhLeu7pVDwrdxLeS4XUOu +4zbqLuz/s91Oc93E0OizevVLhIrrCX+riv0e8/gXB7R/WDeB/4o97M6jGG2g1SbVKw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793632913; h=Received:DKIM-Signature:From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:References:In-Reply-To:To:Cc: X-Mailer:X-Developer-Signature:X-Developer-Key; bh=+Br5BKTNsV9SKJ+VKUXfa+LuXFyw/MNJN1rBJWSG1Dk=; b=qEIaXexBeeOeFyhSwozOxj5XTNyvqnfzjLf8ClkH71cG6HpjtPi5KVl2g7VD4CCIcMeN OuIQ/0u3ouMmxMQzyllZfBgtlOaTFoDoiE8onEep7L9nZqRxRGwn7r7yKr60oOupZiQLf HLlE2OhG4b/gF5HTDbK4iNLMEQgXvzFmmSMRsOqP2cTEJJrgVW1DlwQm9dftjEgqPrDeo E63eNE6v47q9nKuooWga5rjF2iBb6RseqsEqLQuHyEgnyEQRiwCNnK+C9qDLX7gKPQPfx e08HO7UeQWZnsDGqjOV5g81i196an8VaW1VB7KWSNMfs4+m9x1g8XeWvl5C5gTV3kgA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BaGFkmgd; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F36C66080484; Mon, 2 Nov 2026 15:21:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BaGFkmgd Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51A5D1F00A16; Mon, 2 Nov 2026 15:21:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793632912; bh=+Br5BKTNsV9SKJ+VKUXfa+LuXFyw/MNJN1rBJWSG1Dk=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=BaGFkmgddplAg+7kWtOO3Xs2bTNw6C/l7s/H+s/ARAFWAG8PiIzq4DHKs1pIJtkZF MLQLlN2WfsWYgrHwMGc+LaYjthSVIYcPsAQ4ZVs0x8SWftIxeVXIb74Yi6DeQgLPv3 MnvwnjVA4w76GNzJNNroqO1Ub2Of7dy2AD2kO3QhN5NULX8sENf6yS60Ffvc4YDPhz AVUwEuacSjAOwoVTTIoFEsTOOa+8af3coYqbYIzhqzqGrILTs/bIDcsXX7gywt7ryQ fcrmpnyg6ue+WCi9ocPVHrRqPbxVSWScBXs/eHykFP/KwB1QkPorU1BSb4GtLYc/Ew +SFzyKl+Rjtbg== From: Christian Brauner Date: Mon, 02 Nov 2026 16:07:17 +0100 Subject: [PATCH RFC 07/27] ntfs3: let procfs copy in writes to the label file X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261102-work-procfs-fs-v1-7-d09a996317b3@kernel.org> References: <20261102-work-procfs-fs-v1-0-d09a996317b3@kernel.org> In-Reply-To: <20261102-work-procfs-fs-v1-0-d09a996317b3@kernel.org> To: linux-fsdevel@vger.kernel.org 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-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-um@lists.infradead.org, linux-wireless@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, ntfs3@lists.linux.dev, platform-driver-x86@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, linux-sound@vger.kernel.org, netfilter-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, ibm-acpi-devel@lists.sourceforge.net, jfs-discussion@lists.sourceforge.net, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cifs@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-mm@kvack.org, linux-sh@vger.kernel.org, linux-usb@vger.kernel.org, samba-technical@lists.samba.org, sparclinux@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-doc@vger.kernel.org, linux-serial@vger.kernel.org, linux-atm-general@lists.sourceforge.net, Takashi Iwai , linux-input@vger.kernel.org, linux-raid@vger.kernel.org, linux-ext4@vger.kernel.org, linux-modules@vger.kernel.org, linux-debuggers@vger.kernel.org, "Christian Brauner (Amutable)" , Chuck Lever X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2130; i=brauner@kernel.org; h=from:subject:message-id; bh=1xpKZw46Wve9Gi/wwfJco67jsfuLoZVG6n9ZzMkX5cA=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWS9WG70gMfQcsmsxZVZlz3llvU6P9Q+FGFvnWXM+sG1i OvlzHMNHaUsDGJcDLJiiiwO7Sbhcst5KjYbZWrAzGFlAhnCwMUpABPZtYzhr8TWhVUbp6lu+ajh slFF/whfzqNX3hf5107YP/PoQl9+338M/32S/bhdbNlEs9ZN/nX/VOfslLOLVi/+18m6pJt1w+5 V8TwA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Implement ->proc_write_buf() so procfs copies in what is written before it pins the entry, and set the label from that copy. Writes larger than PAGE_SIZE - 1 bytes fail with -EINVAL from procfs now. A write that large only ever worked when most of it was trailing newlines or came after a NUL, ntfs_set_label() refused a label that long with -ENAMETOOLONG or -EFBIG. Signed-off-by: Christian Brauner (Amutable) --- fs/ntfs3/super.c | 27 +++++++++------------------ 1 file changed, 9 insertions(+), 18 deletions(-) diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c index 3d669e957ea4..fca73d2766c0 100644 --- a/fs/ntfs3/super.c +++ b/fs/ntfs3/super.c @@ -536,37 +536,28 @@ static int ntfs3_label_show(struct seq_file *m, void *o) } /* write /proc/fs/ntfs3//label */ -static ssize_t ntfs3_label_write(struct file *file, const char __user *buffer, - size_t count, loff_t *ppos) +static ssize_t ntfs3_label_write(struct file *file, char *buf, size_t count, + loff_t *ppos) { int err; struct super_block *sb = pde_data(file_inode(file)); - ssize_t ret = count; - u8 *label; + size_t len = count; if (sb_rdonly(sb)) return -EROFS; - label = memdup_user(buffer, count); - if (IS_ERR(label)) - return PTR_ERR(label); + while (len > 0 && buf[len - 1] == '\n') + len -= 1; - while (ret > 0 && label[ret - 1] == '\n') - ret -= 1; - - err = ntfs_set_label(sb->s_fs_info, label, ret); + err = ntfs_set_label(sb->s_fs_info, (u8 *)buf, len); if (err < 0) { ntfs_err(sb, "failed (%d) to write label", err); - ret = err; - goto out; + return err; } *ppos += count; - ret = count; -out: - kfree(label); - return ret; + return count; } static const struct proc_ops ntfs3_volinfo_fops = { @@ -575,7 +566,7 @@ static const struct proc_ops ntfs3_volinfo_fops = { static const struct proc_ops ntfs3_label_fops = { .proc_show = ntfs3_label_show, - .proc_write = ntfs3_label_write, + .proc_write_buf = ntfs3_label_write, }; static void ntfs_create_procdir(struct super_block *sb) -- 2.53.0