From 04c494e68a1340cb5c70d4704ac32d863dc64293 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 12 May 2022 14:14:56 -0700 Subject: Revert "tcp/dccp: get rid of inet_twsk_purge()" This reverts commits: 0dad4087a86a2cbe177404dc73f18ada26a2c390 ("tcp/dccp: get rid of inet_twsk_purge()") d507204d3c5cc57d9a8bdf0a477615bb59ea1611 ("tcp/dccp: add tw->tw_bslot") As Leonard pointed out, a newly allocated netns can happen to reuse a freed 'struct net'. While TCP TW timers were covered by my patches, other things were not: 1) Lookups in rx path (INET_MATCH() and INET6_MATCH()), as they look at 4-tuple plus the 'struct net' pointer. 2) /proc/net/tcp[6] and inet_diag, same reason. 3) hashinfo->bhash[], same reason. Fixing all this seems risky, lets instead revert. In the future, we might have a per netns tcp hash table, or a per netns list of timewait sockets... Fixes: 0dad4087a86a ("tcp/dccp: get rid of inet_twsk_purge()") Signed-off-by: Eric Dumazet Reported-by: Leonard Crestez Tested-by: Leonard Crestez Signed-off-by: David S. Miller --- net/ipv4/tcp_ipv4.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/ipv4/tcp_ipv4.c') diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index f9cec624068d..457f5b5d5d4a 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -3173,6 +3173,8 @@ static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list) { struct net *net; + inet_twsk_purge(&tcp_hashinfo, AF_INET); + list_for_each_entry(net, net_exit_list, exit_list) tcp_fastopen_ctx_destroy(net); } -- cgit v1.2.3