From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-2956071-1519782305-2-12354701083905759301 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.249, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='de', MailFrom='org' X-Spam-charsets: X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1519782304; b=tnHSCvGciDi4ImgapWHhxZFL6SX3IwaY1trqHODJFps1Mn1 lVsZvk69VABwfxQv6u5kpP1mQicstPyZQO4OsIk/ftLVsE0ebHXLqONlWE54P4GK FULmqQsyhGzPyFEXS4v9H/mxNMylxMwhRv2xXv6/IhU9eBWDz4rDwZ8HrvHiHpEt JQoimBrwGPn12BJKhw9kuOoZRZUZK9j5iAnpJpv6HWYeHVmcuWXITh16JlZdKFhP 9i1BrZ0gZQPiDx9UM7+FIvtOBjG/ujuqC0HUuLZAMxjDfsF26PeaSFzRusRxYr6R gDpd8pjKUzLr2mebtqWZbyHV9lyxIokITUpnTgA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id:sender :list-id; s=arctest; t=1519782304; bh=eHMe08aO2UCvDQlW4NGq+Dh/B3 jaTPeBrF54BQwtrw0=; b=rUlqKcNJR6HwHtYxWpAFM461h4VQ+pp3zXFQ8KLp1j s2AMRHTkFGILuaYjPAh45b0LSr8RzyAErAGdGn7Qb+qDbGNywRb3ss0I9hgQcdJn 4W4AREFpC3M7aiBkHG1x4ex5mVBDURxq6O3lzxyhqLc7ellSKRkko2jF9XtiJJUy N+uFYkiS4ph/KPwA8vaG7p0+dw/2CCMMHGezqNwNqbwAGpDWv9T3sjQYnyNSgwzs Z8Msq1tl82x5Pug08BF5fQGMqXc9ofqzDiH6YDZAF5WQd/o8MmkCdpqFHRbRMZrE IdesjPuI4+ERaKH5Ce3lvmcZOeUcy3RZsi51tTO4r8og== ARC-Authentication-Results: i=1; mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=dk-develop.de; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=dk-develop.de header.result=pass header_is_org_domain=yes Authentication-Results: mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=dk-develop.de; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=dk-develop.de header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751521AbeB1BpC (ORCPT ); Tue, 27 Feb 2018 20:45:02 -0500 Received: from hs01.dk-develop.de ([213.136.71.231]:43228 "EHLO hs01.dk-develop.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751117AbeB1BpC (ORCPT ); Tue, 27 Feb 2018 20:45:02 -0500 From: Danilo Krummrich To: mcgrof@kernel.org, keescook@chromium.org, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Danilo Krummrich , stable@vger.kernel.org Subject: [PATCH v3 1/2] fs/sysctl: fix potential page fault while unregistering sysctl table Date: Wed, 28 Feb 2018 02:35:05 +0100 Message-Id: <20180228013506.4915-1-danilokrummrich@dk-develop.de> X-Mailer: git-send-email 2.14.1 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 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. This bug has been present since v3.4. Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets") Cc: stable@vger.kernel.org Acked-by: Kees Cook Signed-off-by: Danilo Krummrich --- v2: removed empty line between between sysctl_head_grab and IS_ERR v3: extend commit message, add tags and cc stable --- 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