From: Daniel Borkmann Date: Thu, 31 Oct 2013 08:13:32 +0000 (+0100) Subject: net: sctp: do not trigger BUG_ON in sctp_cmd_delete_tcb X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=7926c1d5be0b7cbe5b8d5c788d7d39237e7b212c;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git net: sctp: do not trigger BUG_ON in sctp_cmd_delete_tcb Introduced in f9e42b853523 ("net: sctp: sideeffect: throw BUG if primary_path is NULL"), we intended to find a buggy assoc that's part of the assoc hash table with a primary_path that is NULL. However, we better remove the BUG_ON for now and find a more suitable place to assert for these things as Mark reports that this also triggers the bug when duplication cookie processing happens, and the assoc is not part of the hash table (so all good in this case). Such a situation can for example easily be reproduced by: tc qdisc add dev eth0 root handle 1: prio bands 2 priomap 1 1 1 1 1 1 tc qdisc add dev eth0 parent 1:2 handle 20: netem loss 20% tc filter add dev eth0 protocol ip parent 1: prio 2 u32 match ip \ protocol 132 0xff match u8 0x0b 0xff at 32 flowid 1:2 This drops 20% of COOKIE-ACK packets. After some follow-up discussion with Vlad we came to the conclusion that for now we should still better remove this BUG_ON() assertion, and come up with two follow-ups later on, that is, i) find a more suitable place for this assertion, and possibly ii) have a special allocator/initializer for such kind of temporary assocs. Reported-by: Mark Thomas Signed-off-by: Vlad Yasevich Signed-off-by: Daniel Borkmann Acked-by: Neil Horman Signed-off-by: David S. Miller --- diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c index 666c66842799..1a6eef39ab2f 100644 --- a/net/sctp/sm_sideeffect.c +++ b/net/sctp/sm_sideeffect.c @@ -860,7 +860,6 @@ static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds, (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK)) return; - BUG_ON(asoc->peer.primary_path == NULL); sctp_unhash_established(asoc); sctp_association_free(asoc); }