netfilter: nf_queue: don't assume sk is full socket

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: ca6fb06518 ("tcp: attach SYNACK messages to request sockets instead of listener")
Tested-by: Oleksandr Natalenko <oleksandr@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Florian Westphal
2022-02-25 14:02:41 +01:00
committed by Greg Kroah-Hartman
parent 4e178ed14b
commit 3b9ba964f7

View File

@@ -46,6 +46,15 @@ void nf_unregister_queue_handler(struct net *net)
} }
EXPORT_SYMBOL(nf_unregister_queue_handler); 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
}
static void nf_queue_entry_release_refs(struct nf_queue_entry *entry) static void nf_queue_entry_release_refs(struct nf_queue_entry *entry)
{ {
struct nf_hook_state *state = &entry->state; struct nf_hook_state *state = &entry->state;
@@ -56,7 +65,7 @@ static void nf_queue_entry_release_refs(struct nf_queue_entry *entry)
if (state->out) if (state->out)
dev_put(state->out); dev_put(state->out);
if (state->sk) if (state->sk)
sock_put(state->sk); nf_queue_sock_put(state->sk);
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
if (entry->physin) if (entry->physin)