From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric W. Biederman" Subject: [PATCH 19/21] userns: xt_owner: Add basic user namespace support. Date: Mon, 13 Aug 2012 13:18:33 -0700 Message-ID: <1344889115-21610-19-git-send-email-ebiederm@xmission.com> References: <87ehnav9n5.fsf@xmission.com> <1344889115-21610-1-git-send-email-ebiederm@xmission.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Patrick McHardy , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jan Engelhardt , "Eric W. Biederman" , David Miller , Pablo Neira Ayuso To: Return-path: In-Reply-To: <1344889115-21610-1-git-send-email-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: netdev.vger.kernel.org From: "Eric W. Biederman" - Only allow adding matches from the initial user namespace - Add the appropriate conversion functions to handle matches against sockets in other user namespaces. Cc: Jan Engelhardt Cc: Patrick McHardy Cc: Pablo Neira Ayuso Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman --- init/Kconfig | 1 - net/netfilter/xt_owner.c | 30 ++++++++++++++++++++++++------ 2 files changed, 24 insertions(+), 7 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index 40f5020..76ffca9 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -943,7 +943,6 @@ config UIDGID_CONVERTED # Networking depends on NET_9P = n - depends on NETFILTER_XT_MATCH_OWNER = n depends on AF_RXRPC = n depends on NET_KEY = n depends on DNS_RESOLVER = n diff --git a/net/netfilter/xt_owner.c b/net/netfilter/xt_owner.c index 772d738..ca2e577 100644 --- a/net/netfilter/xt_owner.c +++ b/net/netfilter/xt_owner.c @@ -17,6 +17,17 @@ #include #include +static int owner_check(const struct xt_mtchk_param *par) +{ + struct xt_owner_match_info *info = par->matchinfo; + + /* For now only allow adding matches from the initial user namespace */ + if ((info->match & (XT_OWNER_UID|XT_OWNER_GID)) && + (current_user_ns() != &init_user_ns)) + return -EINVAL; + return 0; +} + static bool owner_mt(const struct sk_buff *skb, struct xt_action_param *par) { @@ -37,17 +48,23 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par) return ((info->match ^ info->invert) & (XT_OWNER_UID | XT_OWNER_GID)) == 0; - if (info->match & XT_OWNER_UID) - if ((filp->f_cred->fsuid >= info->uid_min && - filp->f_cred->fsuid <= info->uid_max) ^ + if (info->match & XT_OWNER_UID) { + kuid_t uid_min = make_kuid(&init_user_ns, info->uid_min); + kuid_t uid_max = make_kuid(&init_user_ns, info->uid_max); + if ((uid_gte(filp->f_cred->fsuid, uid_min) && + uid_lte(filp->f_cred->fsuid, uid_max)) ^ !(info->invert & XT_OWNER_UID)) return false; + } - if (info->match & XT_OWNER_GID) - if ((filp->f_cred->fsgid >= info->gid_min && - filp->f_cred->fsgid <= info->gid_max) ^ + if (info->match & XT_OWNER_GID) { + kgid_t gid_min = make_kgid(&init_user_ns, info->gid_min); + kgid_t gid_max = make_kgid(&init_user_ns, info->gid_max); + if ((gid_gte(filp->f_cred->fsgid, gid_min) && + gid_lte(filp->f_cred->fsgid, gid_max)) ^ !(info->invert & XT_OWNER_GID)) return false; + } return true; } @@ -56,6 +73,7 @@ static struct xt_match owner_mt_reg __read_mostly = { .name = "owner", .revision = 1, .family = NFPROTO_UNSPEC, + .checkentry = owner_check, .match = owner_mt, .matchsize = sizeof(struct xt_owner_match_info), .hooks = (1 << NF_INET_LOCAL_OUT) | -- 1.7.5.4