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| author | Xin Long <lucien.xin@gmail.com> | 2021-05-03 04:41:20 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-22 10:38:28 +0200 |
| commit | dc9d299c1a189930dc9501458ffcdad84c6ddf96 (patch) | |
| tree | 257ed5fe5d1496fb4b7522d524c7af8e0a205783 | |
| parent | 5b5c74cf45077c49e69c2601e67d472e9944bc1b (diff) | |
sctp: fix a SCTP_MIB_CURRESTAB leak in sctp_sf_do_dupcook_b
[ Upstream commit f282df0391267fb2b263da1cc3233aa6fb81defc ]
Normally SCTP_MIB_CURRESTAB is always incremented once asoc enter into
ESTABLISHED from the state < ESTABLISHED and decremented when the asoc
is being deleted.
However, in sctp_sf_do_dupcook_b(), the asoc's state can be changed to
ESTABLISHED from the state >= ESTABLISHED where it shouldn't increment
SCTP_MIB_CURRESTAB. Otherwise, one asoc may increment MIB_CURRESTAB
multiple times but only decrement once at the end.
I was able to reproduce it by using scapy to do the 4-way shakehands,
after that I replayed the COOKIE-ECHO chunk with 'peer_vtag' field
changed to different values, and SCTP_MIB_CURRESTAB was incremented
multiple times and never went back to 0 even when the asoc was freed.
This patch is to fix it by only incrementing SCTP_MIB_CURRESTAB when
the state < ESTABLISHED in sctp_sf_do_dupcook_b().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/sctp/sm_statefuns.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index a9a72f7e0cd7..a9ba6f2bb8c8 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -1851,7 +1851,8 @@ static sctp_disposition_t sctp_sf_do_dupcook_b(struct net *net, sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc)); sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, SCTP_STATE(SCTP_STATE_ESTABLISHED)); - SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); + if (asoc->state < SCTP_STATE_ESTABLISHED) + SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); repl = sctp_make_cookie_ack(new_asoc, chunk); |