Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932824AbbG1JxP (ORCPT ); Tue, 28 Jul 2015 05:53:15 -0400 Received: from mx2.suse.de ([195.135.220.15]:57911 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932102AbbG1JxH (ORCPT ); Tue, 28 Jul 2015 05:53:07 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, "Eric W. Biederman" , Jiri Slaby Subject: [PATCH 3.12 095/124] vfs: Ignore unlocked mounts in fs_fully_visible Date: Tue, 28 Jul 2015 11:52:36 +0200 Message-Id: <287bb65a24cc8f3b4b834213cc2145f1b282323c.1438076484.git.jslaby@suse.cz> X-Mailer: git-send-email 2.4.6 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1636 Lines: 48 From: "Eric W. Biederman" 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit ceeb0e5d39fcdf4dca2c997bf225c7fc49200b37 upstream. Limit the mounts fs_fully_visible considers to locked mounts. Unlocked can always be unmounted so considering them adds hassle but no security benefit. Signed-off-by: "Eric W. Biederman" Signed-off-by: Jiri Slaby --- fs/namespace.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 9ae6837ef5bf..bdc6223a7500 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2939,11 +2939,15 @@ bool fs_fully_visible(struct file_system_type *type) if (mnt->mnt.mnt_root != mnt->mnt.mnt_sb->s_root) continue; - /* This mount is not fully visible if there are any child mounts - * that cover anything except for empty directories. + /* This mount is not fully visible if there are any + * locked child mounts that cover anything except for + * empty directories. */ list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) { struct inode *inode = child->mnt_mountpoint->d_inode; + /* Only worry about locked mounts */ + if (!(mnt->mnt.mnt_flags & MNT_LOCKED)) + continue; if (!S_ISDIR(inode->i_mode)) goto next; if (inode->i_nlink > 2) -- 2.4.6 -- 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/