From: Jeremy Kerr Date: Tue, 24 Jan 2023 02:01:06 +0000 (+0800) Subject: net: mctp: mark socks as dead on unhash, prevent re-add X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b98e1a04e27fddfdc808bf46fe78eca30db89ab3;p=linux.git net: mctp: mark socks as dead on unhash, prevent re-add Once a socket has been unhashed, we want to prevent it from being re-used in a sk_key entry as part of a routing operation. This change marks the sk as SOCK_DEAD on unhash, which prevents addition into the net's key list. We need to do this during the key add path, rather than key lookup, as we release the net keys_lock between those operations. Fixes: 4a992bbd3650 ("mctp: Implement message fragmentation & reassembly") Signed-off-by: Jeremy Kerr Signed-off-by: David S. Miller --- diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c index fb6ae3110528a..45bbe3e54cc28 100644 --- a/net/mctp/af_mctp.c +++ b/net/mctp/af_mctp.c @@ -577,6 +577,7 @@ static void mctp_sk_unhash(struct sock *sk) spin_lock_irqsave(&key->lock, fl2); __mctp_key_remove(key, net, fl2, MCTP_TRACE_KEY_CLOSED); } + sock_set_flag(sk, SOCK_DEAD); spin_unlock_irqrestore(&net->mctp.keys_lock, flags); /* Since there are no more tag allocations (we have removed all of the diff --git a/net/mctp/route.c b/net/mctp/route.c index 06c0de21984d9..f51a05ec71624 100644 --- a/net/mctp/route.c +++ b/net/mctp/route.c @@ -179,6 +179,11 @@ static int mctp_key_add(struct mctp_sk_key *key, struct mctp_sock *msk) spin_lock_irqsave(&net->mctp.keys_lock, flags); + if (sock_flag(&msk->sk, SOCK_DEAD)) { + rc = -EINVAL; + goto out_unlock; + } + hlist_for_each_entry(tmp, &net->mctp.keys, hlist) { if (mctp_key_match(tmp, key->local_addr, key->peer_addr, key->tag)) { @@ -200,6 +205,7 @@ static int mctp_key_add(struct mctp_sk_key *key, struct mctp_sock *msk) hlist_add_head(&key->sklist, &msk->keys); } +out_unlock: spin_unlock_irqrestore(&net->mctp.keys_lock, flags); return rc;