From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9A0662405F9; Tue, 11 Mar 2025 15:14:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741706079; cv=none; b=OKp5gc7OwT+RtvD7ArPQzvSE5osboQumU02xB5+4IqsnEsG6tu1tPWtPm44hVsSpQrsFbEKhY+rfcNqP9zGQhdUGOhecgAvXSHIEEaA9YguIQSJSZs+1qrQnZcRogBasZqqk2LwxPff5Pa2RlnQNUsXqVVhxrq9UkCmX5N7CXWI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741706079; c=relaxed/simple; bh=csWSJo0/bwr+9SGed7myAdPc2+2iciwa5ELr9ImyQmk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WEzNkIukW+ljkPK5o8Ib6UuAJRvcU+IVfS2+XgKkgZdX8Qs2LQiWoSyGx3ePeVYjH56uieTWlkruFeaNgitDP/82S/uK4LLLlwdM0qS9oBQ8q/7d4fbL0Ec9iMenYsmpJsuE2IWd5xoclxtYuehI4EZY9POVMfGh29brDJPkcug= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NhcnuvPK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="NhcnuvPK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1907C4CEE9; Tue, 11 Mar 2025 15:14:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741706079; bh=csWSJo0/bwr+9SGed7myAdPc2+2iciwa5ELr9ImyQmk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NhcnuvPKDfV9LeOHiRITocxbIUizyiHMp+IGPhxmjO/3QmiLq94iks5y5FVgw5XXS JidDtJrNRIGKm8KEk2qPvSrPIuDNTiNllCvO14KZiT9tFEAId7p/XQ/LJ0dLdVb6o5 2bljDHuoZpqYChvvRhU84eD72PLAJ/YpH74cEJBg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Amir Goldstein , Zicheng Qu , Christian Brauner Subject: [PATCH 5.4 255/328] acct: block access to kernel internal filesystems Date: Tue, 11 Mar 2025 16:00:25 +0100 Message-ID: <20250311145725.044618636@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250311145714.865727435@linuxfoundation.org> References: <20250311145714.865727435@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christian Brauner commit 890ed45bde808c422c3c27d3285fc45affa0f930 upstream. There's no point in allowing anything kernel internal nor procfs or sysfs. Link: https://lore.kernel.org/r/20250127091811.3183623-1-quzicheng@huawei.com Link: https://lore.kernel.org/r/20250211-work-acct-v1-2-1c16aecab8b3@kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Amir Goldstein Reported-by: Zicheng Qu Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman --- kernel/acct.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/kernel/acct.c +++ b/kernel/acct.c @@ -216,6 +216,20 @@ static int acct_on(struct filename *path return -EACCES; } + /* Exclude kernel kernel internal filesystems. */ + if (file_inode(file)->i_sb->s_flags & (SB_NOUSER | SB_KERNMOUNT)) { + kfree(acct); + filp_close(file, NULL); + return -EINVAL; + } + + /* Exclude procfs and sysfs. */ + if (file_inode(file)->i_sb->s_iflags & SB_I_USERNS_VISIBLE) { + kfree(acct); + filp_close(file, NULL); + return -EINVAL; + } + if (!(file->f_mode & FMODE_CAN_WRITE)) { kfree(acct); filp_close(file, NULL);