From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751752AbeB0XcC (ORCPT ); Tue, 27 Feb 2018 18:32:02 -0500 Received: from hs01.dk-develop.de ([213.136.71.231]:35134 "EHLO hs01.dk-develop.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751631AbeB0XcB (ORCPT ); Tue, 27 Feb 2018 18:32:01 -0500 From: Danilo Krummrich To: mcgrof@kernel.org, keescook@chromium.org Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Danilo Krummrich Subject: [PATCH v2 1/2] fs/sysctl: fix potential page fault while unregistering sysctl table Date: Wed, 28 Feb 2018 00:31:55 +0100 Message-Id: <20180227233156.29826-1-danilokrummrich@dk-develop.de> X-Mailer: git-send-email 2.14.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org proc_sys_link_fill_cache() does not take currently unregistering sysctl tables into account, which might result into a page fault in sysctl_follow_link() - add a check to fix it. Signed-off-by: Danilo Krummrich --- v2: removed empty line between between sysctl_head_grab and IS_ERR --- fs/proc/proc_sysctl.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index c5cbbdff3c3d..82ac5f682b73 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -707,7 +707,10 @@ static bool proc_sys_link_fill_cache(struct file *file, struct ctl_table *table) { bool ret = true; + head = sysctl_head_grab(head); + if (IS_ERR(head)) + return false; if (S_ISLNK(table->mode)) { /* It is not an error if we can not follow the link ignore it */ -- 2.14.1