From: Florian Westphal Date: Tue, 24 Nov 2020 16:24:46 +0000 (+0100) Subject: mptcp: put reference in mptcp timeout timer X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b6d69fc8e8cfd1694e709c16e6192339bde68923;p=linux.git mptcp: put reference in mptcp timeout timer On close this timer might be scheduled. mptcp uses sk_reset_timer for this, so the a reference on the mptcp socket is taken. This causes a refcount leak which can for example be reproduced with 'mp_join_server_v4.pkt' from the mptcp-packetdrill repo. The leak has nothing to do with join requests, v1_mp_capable_bind_no_cs.pkt works too when replacing the last ack mpcapable to v1 instead of v0. unreferenced object 0xffff888109bba040 (size 2744): comm "packetdrill", [..] backtrace: [..] sk_prot_alloc.isra.0+0x2b/0xc0 [..] sk_clone_lock+0x2f/0x740 [..] mptcp_sk_clone+0x33/0x1a0 [..] subflow_syn_recv_sock+0x2b1/0x690 [..] Fixes: e16163b6e2b7 ("mptcp: refactor shutdown and close") Cc: Davide Caratti Signed-off-by: Florian Westphal Acked-by: Paolo Abeni Link: https://lore.kernel.org/r/20201124162446.11448-1-fw@strlen.de Signed-off-by: Jakub Kicinski --- diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 4b7794835feac..dc979571f5614 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1710,6 +1710,7 @@ static void mptcp_timeout_timer(struct timer_list *t) struct sock *sk = from_timer(sk, t, sk_timer); mptcp_schedule_work(sk); + sock_put(sk); } /* Find an idle subflow. Return NULL if there is unacked data at tcp