smpp: Unset esme->acl on socket close
We set acl->esme during _process_bind(), but we don't clear it
in case the TCP connection for the ESME is dead. This leads to
a stale acl->esme pointer, which we will attempt to dereference
the next time a SMS is delivered to a route pointing to this acl,
where it will be a heap use-after-free.
This was discovered using AddressSanitizer and MSC_Tests.ttcn
Closes: OS#3168
Change-Id: I1f140d7f9c7d89f200ddbcd81a8df66de69fb3e4
diff --git a/src/libmsc/smpp_smsc.c b/src/libmsc/smpp_smsc.c
index b889b52..7bbb0a4 100644
--- a/src/libmsc/smpp_smsc.c
+++ b/src/libmsc/smpp_smsc.c
@@ -249,6 +249,8 @@
}
smpp_cmd_flush_pending(esme);
llist_del(&esme->list);
+ if (esme->acl)
+ esme->acl->esme = NULL;
talloc_free(esme);
}
@@ -875,6 +877,8 @@
osmo_fd_unregister(&esme->wqueue.bfd);
close(esme->wqueue.bfd.fd);
esme->wqueue.bfd.fd = -1;
+ if (esme->acl)
+ esme->acl->esme = NULL;
smpp_esme_put(esme);
return 0;
@@ -891,6 +895,8 @@
osmo_fd_unregister(&esme->wqueue.bfd);
close(esme->wqueue.bfd.fd);
esme->wqueue.bfd.fd = -1;
+ if (esme->acl)
+ esme->acl->esme = NULL;
smpp_esme_put(esme);
} else if (rc < msgb_length(msg)) {
LOGP(DSMPP, LOGL_ERROR, "[%s] Short write\n", esme->system_id);