sctp: sctp should release assoc when sctp_make_abort_user return NULL in sctp_close

In sctp_close, sctp_make_abort_user may return NULL because of memory
allocation failure. If this happens, it will bypass any state change
and never free the assoc. The assoc has no chance to be freed and it
will be kept in memory with the state it had even after the socket is
closed by sctp_close().

So if sctp_make_abort_user fails to allocate memory, we should abort
the asoc via sctp_primitive_ABORT as well. Just like the annotation in
sctp_sf_cookie_wait_prm_abort and sctp_sf_do_9_1_prm_abort said,
"Even if we can't send the ABORT due to low memory delete the TCB.
This is a departure from our typical NOMEM handling".

But then the chunk is NULL (low memory) and the SCTP_CMD_REPLY cmd would
dereference the chunk pointer, and system crash. So we should add
SCTP_CMD_REPLY cmd only when the chunk is not NULL, just like other
places where it adds SCTP_CMD_REPLY cmd.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index cd34a4a3406578954d5831b8304162c7102d8cec..22c2bf367d7e8c7025065f33eabfd7e93a7f4021 100644 (file)
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -4829,7 +4829,8 @@ sctp_disposition_t sctp_sf_do_9_1_prm_abort(
 
        retval = SCTP_DISPOSITION_CONSUME;
 
-       sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
+       if (abort)
+               sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
 
        /* Even if we can't send the ABORT due to low memory delete the
         * TCB.  This is a departure from our typical NOMEM handling.
@@ -4966,7 +4967,8 @@ sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
                        SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
        retval = SCTP_DISPOSITION_CONSUME;
 
-       sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
+       if (abort)
+               sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
 
        sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
                        SCTP_STATE(SCTP_STATE_CLOSED));

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 529ed357a2cf1543123fa85e0c55fceb76706be3..ef1d90fdc773d2ca4104c9dabc96d1058e99629a 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1516,8 +1516,7 @@ static void sctp_close(struct sock *sk, long timeout)
                        struct sctp_chunk *chunk;
 
                        chunk = sctp_make_abort_user(asoc, NULL, 0);
-                       if (chunk)
-                               sctp_primitive_ABORT(net, asoc, chunk);
+                       sctp_primitive_ABORT(net, asoc, chunk);
                } else
                        sctp_primitive_SHUTDOWN(net, asoc, NULL);
        }