Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3C4E643B6F2; Mon, 17 Aug 2026 14:17:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786976256; cv=none; b=E/qnOTQRxju0ON5uxM/+UGtp7SUOfJLfYxWdCy5LePRlgy6ObTUhNXQGM0pDNA5/VbrlZAiSqhYsDm7La8xmkp+ZJNlktKN2ZkX/fd1S/+DAxIFe5kBaUpwbfgZplGZ8N5pi5VIFAjFETFr1ixdu+uzRKccD3hhowUIFZ0KrBCE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786976256; c=relaxed/simple; bh=4/2hgGjwdP2U8CPQlNh9nNZejRgjvbpfVk7Rf2VwrgU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KlJucQR9HezPGNuEG1XyNKJR5W8tpse4UqYl3jp/5XU7LVPqZKlardZZvchH4aHZ/ph2v5RhTd3mYZ8/F8nLb96V6wvRfKYSlebp4bxwVmGIMI2wNpi2ZcjKrduOwRo15NFaijDbLegslXF5N5E5g1QAu+wRA84vZZ0AGfvRuVo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1k8xbJMH; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1k8xbJMH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 953911F000E9; Mon, 17 Aug 2026 14:17:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786976255; bh=zy0swo2pWr7kr0dHhFfkBRyr7o4iqKIOE8yoqLGxnMk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1k8xbJMHrmWsBZBRXKGzrsMZWjjF/YmJlap4j0BRg17X5uU7ioSDr5YwtnAqTKisU vuHXr+7syINeYuzJrasGSYbgHJYkva0WBiJPIB+oomJXGnWf0/janQBNhRA74Egsog 1/3/wObrQ8GubThWZ2fl42uOfhR0GYZxLBnF43Hs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Denis Arefev , Al Viro , "Christian Brauner (Amutable)" , Sasha Levin Subject: [PATCH 5.10 309/389] mount: honour SB_NOUSER in the new mount API Date: Mon, 17 Aug 2026 15:32:28 +0200 Message-ID: <20260817132551.063411212@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132538.796021292@linuxfoundation.org> References: <20260817132538.796021292@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro [ Upstream commit 6dd3c6884cd9defb511284b566cef5ac8f657dbf ] One should *not* be allowed to mount one of those, new API or not. Reported-by: Denis Arefev Signed-off-by: Al Viro Link: https://patch.msgid.link/20260602020444.GP2636677@ZenIV Signed-off-by: Christian Brauner (Amutable) [Denis: rename new_mnt -> newmount.mnt] [Denis: use goto err_unlock instead of direct return] Signed-off-by: Denis Arefev Signed-off-by: Sasha Levin --- fs/namespace.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/namespace.c b/fs/namespace.c index e9b8d516f1919..fcb9ab4617754 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3657,6 +3657,11 @@ SYSCALL_DEFINE3(fsmount, int, fs_fd, unsigned int, flags, ret = PTR_ERR(newmount.mnt); goto err_unlock; } + if (newmount.mnt->mnt_sb->s_flags & SB_NOUSER) { + mntput(newmount.mnt); + ret = -EINVAL; + goto err_unlock; + } newmount.dentry = dget(fc->root); newmount.mnt->mnt_flags = mnt_flags; -- 2.53.0