From ed77de9fc69076e6e7c85edf7c1b70650f53121a Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Wed, 9 Nov 2005 13:02:16 -0800 Subject: [PATCH] [NETFILTER] nfnetlink: only load subsystems if CAP_NET_ADMIN is set Without this patch, any user can cause nfnetlink subsystems to be autoloaded. Those subsystems however could add significant processing overhead to packet processing, and would refuse any configuration messages from non-CAP_NET_ADMIN processes anyway. This patch follows a suggestion from Patrick McHardy. Signed-off-by: Harald Welte Signed-off-by: David S. Miller --- net/netfilter/nfnetlink.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index f8bd7c7e7921..83f4c53030fc 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -240,15 +240,18 @@ static inline int nfnetlink_rcv_msg(struct sk_buff *skb, ss = nfnetlink_get_subsys(type); if (!ss) { #ifdef CONFIG_KMOD - /* 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 (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); + } if (!ss) #endif - goto err_inval; + goto err_inval; } nc = nfnetlink_find_client(type, ss); -- 2.20.1