From 37d2e7a20d745035b600f1a6be56cbb9c7259419 Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Mon, 14 Nov 2005 15:24:59 -0800 Subject: [PATCH] [NETFILTER] nfnetlink: unconditionally require CAP_NET_ADMIN This patch unconditionally requires CAP_NET_ADMIN for all nfnetlink messages. It also removes the per-message cap_required field, since all existing subsystems use CAP_NET_ADMIN for all their messages anyway. Patrick McHardy owes me a beer if we ever need to re-introduce this. Signed-off-by: Harald Welte Signed-off-by: David S. Miller --- include/linux/netfilter/nfnetlink.h | 1 - net/ipv4/netfilter/ip_conntrack_netlink.c | 21 ++++++----------- net/netfilter/nfnetlink.c | 28 ++++++++++------------- net/netfilter/nfnetlink_log.c | 6 ++--- net/netfilter/nfnetlink_queue.c | 9 +++----- 5 files changed, 24 insertions(+), 41 deletions(-) diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h index 8be2f840a557..934a2479f160 100644 --- a/include/linux/netfilter/nfnetlink.h +++ b/include/linux/netfilter/nfnetlink.h @@ -112,7 +112,6 @@ struct nfnl_callback { int (*call)(struct sock *nl, struct sk_buff *skb, struct nlmsghdr *nlh, struct nfattr *cda[], int *errp); - kernel_cap_t cap_required; /* capabilities required for this msg */ u_int16_t attr_count; /* number of nfattr's */ }; diff --git a/net/ipv4/netfilter/ip_conntrack_netlink.c b/net/ipv4/netfilter/ip_conntrack_netlink.c index f5e5e3158670..de9f4464438d 100644 --- a/net/ipv4/netfilter/ip_conntrack_netlink.c +++ b/net/ipv4/netfilter/ip_conntrack_netlink.c @@ -1543,29 +1543,22 @@ static struct notifier_block ctnl_notifier_exp = { static struct nfnl_callback ctnl_cb[IPCTNL_MSG_MAX] = { [IPCTNL_MSG_CT_NEW] = { .call = ctnetlink_new_conntrack, - .attr_count = CTA_MAX, - .cap_required = CAP_NET_ADMIN }, + .attr_count = CTA_MAX, }, [IPCTNL_MSG_CT_GET] = { .call = ctnetlink_get_conntrack, - .attr_count = CTA_MAX, - .cap_required = CAP_NET_ADMIN }, + .attr_count = CTA_MAX, }, [IPCTNL_MSG_CT_DELETE] = { .call = ctnetlink_del_conntrack, - .attr_count = CTA_MAX, - .cap_required = CAP_NET_ADMIN }, + .attr_count = CTA_MAX, }, [IPCTNL_MSG_CT_GET_CTRZERO] = { .call = ctnetlink_get_conntrack, - .attr_count = CTA_MAX, - .cap_required = CAP_NET_ADMIN }, + .attr_count = CTA_MAX, }, }; static struct nfnl_callback ctnl_exp_cb[IPCTNL_MSG_EXP_MAX] = { [IPCTNL_MSG_EXP_GET] = { .call = ctnetlink_get_expect, - .attr_count = CTA_EXPECT_MAX, - .cap_required = CAP_NET_ADMIN }, + .attr_count = CTA_EXPECT_MAX, }, [IPCTNL_MSG_EXP_NEW] = { .call = ctnetlink_new_expect, - .attr_count = CTA_EXPECT_MAX, - .cap_required = CAP_NET_ADMIN }, + .attr_count = CTA_EXPECT_MAX, }, [IPCTNL_MSG_EXP_DELETE] = { .call = ctnetlink_del_expect, - .attr_count = CTA_EXPECT_MAX, - .cap_required = CAP_NET_ADMIN }, + .attr_count = CTA_EXPECT_MAX, }, }; static struct nfnetlink_subsystem ctnl_subsys = { diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index 83f4c53030fc..a60c59b97631 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -223,6 +223,12 @@ static inline int nfnetlink_rcv_msg(struct sk_buff *skb, NFNL_SUBSYS_ID(nlh->nlmsg_type), NFNL_MSG_TYPE(nlh->nlmsg_type)); + if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN)) { + DEBUGP("missing CAP_NET_ADMIN\n"); + *errp = -EPERM; + return -1; + } + /* Only requests are handled by kernel now. */ if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) { DEBUGP("received non-request message\n"); @@ -240,15 +246,12 @@ static inline int nfnetlink_rcv_msg(struct sk_buff *skb, ss = nfnetlink_get_subsys(type); if (!ss) { #ifdef CONFIG_KMOD - if (cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN)) { - /* don't call nfnl_shunlock, since it would reenter - * with further packet processing */ - up(&nfnl_sem); - request_module("nfnetlink-subsys-%d", - NFNL_SUBSYS_ID(type)); - nfnl_shlock(); - ss = nfnetlink_get_subsys(type); - } + /* don't call nfnl_shunlock, since it would reenter + * with further packet processing */ + up(&nfnl_sem); + request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type)); + nfnl_shlock(); + ss = nfnetlink_get_subsys(type); if (!ss) #endif goto err_inval; @@ -260,13 +263,6 @@ static inline int nfnetlink_rcv_msg(struct sk_buff *skb, goto err_inval; } - if (nc->cap_required && - !cap_raised(NETLINK_CB(skb).eff_cap, nc->cap_required)) { - DEBUGP("permission denied for type %d\n", type); - *errp = -EPERM; - return -1; - } - { u_int16_t attr_count = ss->cb[NFNL_MSG_TYPE(nlh->nlmsg_type)].attr_count; diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index d194676f3655..cba63729313d 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -862,11 +862,9 @@ out_put: static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = { [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp, - .attr_count = NFULA_MAX, - .cap_required = CAP_NET_ADMIN, }, + .attr_count = NFULA_MAX, }, [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config, - .attr_count = NFULA_CFG_MAX, - .cap_required = CAP_NET_ADMIN }, + .attr_count = NFULA_CFG_MAX, }, }; static struct nfnetlink_subsystem nfulnl_subsys = { diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index f065a6c94953..f28460b61e47 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -931,14 +931,11 @@ out_put: static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = { [NFQNL_MSG_PACKET] = { .call = nfqnl_recv_unsupp, - .attr_count = NFQA_MAX, - .cap_required = CAP_NET_ADMIN }, + .attr_count = NFQA_MAX, }, [NFQNL_MSG_VERDICT] = { .call = nfqnl_recv_verdict, - .attr_count = NFQA_MAX, - .cap_required = CAP_NET_ADMIN }, + .attr_count = NFQA_MAX, }, [NFQNL_MSG_CONFIG] = { .call = nfqnl_recv_config, - .attr_count = NFQA_CFG_MAX, - .cap_required = CAP_NET_ADMIN }, + .attr_count = NFQA_CFG_MAX, }, }; static struct nfnetlink_subsystem nfqnl_subsys = {