From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Brauner Subject: [PATCH 08/24] inode: inode_owner_or_capable(): handle fsid mappings Date: Tue, 11 Feb 2020 17:57:37 +0100 Message-ID: <20200211165753.356508-9-christian.brauner@ubuntu.com> References: <20200211165753.356508-1-christian.brauner@ubuntu.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200211165753.356508-1-christian.brauner@ubuntu.com> Sender: linux-kernel-owner@vger.kernel.org To: =?UTF-8?q?St=C3=A9phane=20Graber?= , "Eric W. Biederman" , Aleksa Sarai , Jann Horn Cc: smbarber@chromium.org, Alexander Viro , Alexey Dobriyan , Serge Hallyn , James Morris , Kees Cook , Jonathan Corbet , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, containers@lists.linux-foundation.org, linux-security-module@vger.kernel.org, linux-api@vger.kernel.org, Christian Brauner List-Id: linux-api@vger.kernel.org Switch inode_owner_or_capable() to lookup fsids in the fsid mappings. If no fsid mappings are setup the behavior is unchanged, i.e. fsids are looked up in the id mappings. Filesystems that share a superblock in all user namespaces they are mounted in will retain their old semantics even with the introduction of fsidmappings. Signed-off-by: Christian Brauner --- fs/inode.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/inode.c b/fs/inode.c index 96d62d97694e..c1ed43c5054c 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include "internal.h" @@ -2083,8 +2084,12 @@ bool inode_owner_or_capable(const struct inode *inode) return true; ns = current_user_ns(); - if (kuid_has_mapping(ns, inode->i_uid) && ns_capable(ns, CAP_FOWNER)) + if (is_userns_visible(inode->i_sb->s_iflags)) { + if (kuid_has_mapping(ns, inode->i_uid) && ns_capable(ns, CAP_FOWNER)) + return true; + } else if (kfsuid_has_mapping(ns, inode->i_uid) && ns_capable(ns, CAP_FOWNER)) { return true; + } return false; } EXPORT_SYMBOL(inode_owner_or_capable); -- 2.25.0