Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755078AbbGPBLc (ORCPT ); Wed, 15 Jul 2015 21:11:32 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:56088 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932080AbbGPBL2 (ORCPT ); Wed, 15 Jul 2015 21:11:28 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "Eric W. Biederman" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 184/251] vfs: Ignore unlocked mounts in fs_fully_visible Date: Wed, 15 Jul 2015 18:08:25 -0700 Message-Id: <1437008972-9140-185-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1437008972-9140-1-git-send-email-kamal@canonical.com> References: <1437008972-9140-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1699 Lines: 48 3.19.8-ckt4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: "Eric W. Biederman" 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: Kamal Mostafa --- fs/namespace.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 34669cc..3d29b31 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3166,11 +3166,15 @@ static bool fs_fully_visible(struct file_system_type *type, int *new_mnt_flags) ((mnt->mnt.mnt_flags & MNT_ATIME_MASK) != (new_flags & MNT_ATIME_MASK))) 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) -- 1.9.1 -- 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/