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 81B2F22FF40; Mon, 10 Mar 2025 18:17:12 +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=1741630632; cv=none; b=k9ifTJHG+diZl+Ze7ykABiGQExjZgvxv8FB5o5rG/x67xuulq/Op2vOztqZB9zu086ljhvem0VCkPtjI1G1JW+Z18yQx+T9x+h7mvxWNRIVQGjR5yMpc3fKyaex3DL9rBQWkFCMinaf8uNXTKJ6R9oE1fWBGvyRzIhMiK0EAbVM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741630632; c=relaxed/simple; bh=zYnDHOFnp5mqZzvAxCypTdclzwTwhkfXx/l6+C4eFD4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tOfg6vBt8DfD+9mn8pScDbSNZAj58MXElGXUceSrCn8mMdg4r60TkncZL3xO1XmDJN+1MQZOIxcgH7JIQLNXGKVMiCDWBj/tmqI9XlZMXPGYnDG44gCbRllquHDU/o96cp0XJwzeqwoiVPCA10EPR6E0F8+BuaTZ+Z0tKO9sMIk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HkHreA86; 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="HkHreA86" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 047D6C4CEE5; Mon, 10 Mar 2025 18:17:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741630632; bh=zYnDHOFnp5mqZzvAxCypTdclzwTwhkfXx/l6+C4eFD4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HkHreA86T9R1HHoO0m1JuuxPYK1qASn5nJH1zhN/VpSCVphqzLAGqNvpin74Tj53n m3jPueaDJJHxdGTW0emgBLRb8MiIbaMrGY0h6QpJen6bV68xkFnKfO9X5LtEdWzQWt 90+WhYH3o/8EWMp5pevw1s36PBTuGgwMIx9ubNow= 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 5.15 481/620] acct: block access to kernel internal filesystems Date: Mon, 10 Mar 2025 18:05:27 +0100 Message-ID: <20250310170604.559320445@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250310170545.553361750@linuxfoundation.org> References: <20250310170545.553361750@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 5.15-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 @@ -225,6 +225,20 @@ 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);