Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933794Ab3DBWbz (ORCPT ); Tue, 2 Apr 2013 18:31:55 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33414 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933631Ab3DBWOH (ORCPT ); Tue, 2 Apr 2013 18:14:07 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dave Jones , Sasha Levin , Ming Lei Subject: [ 10/68] sysfs: handle failure path correctly for readdir() Date: Tue, 2 Apr 2013 15:12:59 -0700 Message-Id: <20130402221331.128188706@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130402221329.915209206@linuxfoundation.org> References: <20130402221329.915209206@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1727 Lines: 53 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ming Lei commit e5110f411d2ee35bf8d202ccca2e89c633060dca upstream. In case of 'if (filp->f_pos == 0 or 1)' of sysfs_readdir(), the failure from filldir() isn't handled, and the reference counter of the sysfs_dirent object pointed by filp->private_data will be released without clearing filp->private_data, so use after free bug will be triggered later. This patch returns immeadiately under the situation for fixing the bug, and it is reasonable to return from readdir() when filldir() fails. Reported-by: Dave Jones Tested-by: Sasha Levin Signed-off-by: Ming Lei Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -1002,6 +1002,8 @@ static int sysfs_readdir(struct file * f ino = parent_sd->s_ino; if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0) filp->f_pos++; + else + return 0; } if (filp->f_pos == 1) { if (parent_sd->s_parent) @@ -1010,6 +1012,8 @@ static int sysfs_readdir(struct file * f ino = parent_sd->s_ino; if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0) filp->f_pos++; + else + return 0; } mutex_lock(&sysfs_mutex); for (pos = sysfs_dir_pos(ns, parent_sd, filp->f_pos, pos); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/