From 7078f0dd20c2d448c6af3c2451eefb0b84070e25 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Sat, 7 May 2022 08:24:26 +0000 Subject: [PATCH] netfilter: nf_queue: don't assume sk is full socket stable inclusion from linux-4.19.233 commit 6d9719ef61a99d1ed750b510d32620a6c4bb7397 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5646A CVE: NA -------------------------------- commit 747670fd9a2d1b7774030dba65ca022ba442ce71 upstream. There is no guarantee that state->sk refers to a full socket. If refcount transitions to 0, sock_put calls sk_free which then ends up with garbage fields. I'd like to thank Oleksandr Natalenko and Jiri Benc for considerable debug work and pointing out state->sk oddities. Fixes: ca6fb0651883 ("tcp: attach SYNACK messages to request sockets instead of listener") Tested-by: Oleksandr Natalenko Signed-off-by: Florian Westphal Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yongqiang Liu --- net/netfilter/nf_queue.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c index ee6d98355081..ca0c9a9dcdc8 100644 --- a/net/netfilter/nf_queue.c +++ b/net/netfilter/nf_queue.c @@ -46,6 +46,15 @@ void nf_unregister_queue_handler(struct net *net) } EXPORT_SYMBOL(nf_unregister_queue_handler); +static void nf_queue_sock_put(struct sock *sk) +{ +#ifdef CONFIG_INET + sock_gen_put(sk); +#else + sock_put(sk); +#endif +} + void nf_queue_entry_release_refs(struct nf_queue_entry *entry) { struct nf_hook_state *state = &entry->state; @@ -56,7 +65,7 @@ void nf_queue_entry_release_refs(struct nf_queue_entry *entry) if (state->out) dev_put(state->out); if (state->sk) - sock_put(state->sk); + nf_queue_sock_put(state->sk); #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) if (entry->skb->nf_bridge) { struct net_device *physdev; -- GitLab