smpp_smsc: Check that the size is large enough to hold actual data

The first 4 bytes are the length including the length field. For
length < 4 the subsequent msgb_put(msg, sizeof(uint32_t)) will fail,
resulting in an abort. The code also expects (in smpp_msgb_cmdid()) the
existence of 4 more bytes for the SMPP command ID.

This patch checks that the length received is large enough to hold all
8 bytes in the msgb and drops the connection if that's not the case.

The issue is reproducible with:
echo -e "\x00\x00\x00\x02\x00" |socat stdin tcp:localhost:2775
This commit is contained in:
Daniel Willmann 2014-01-17 15:17:36 +01:00 committed by Holger Hans Peter Freyther
parent a4540b2c3b
commit b6f01e77b1
1 changed files with 6 additions and 0 deletions

View File

@ -803,6 +803,12 @@ static int esme_link_read_cb(struct osmo_fd *ofd)
if (esme->read_idx >= sizeof(uint32_t)) {
esme->read_len = ntohl(len);
if (esme->read_len < 8) {
LOGP(DSMPP, LOGL_ERROR, "[%s] read length too small %u\n",
esme->system_id, esme->read_len);
goto dead_socket;
}
msg = msgb_alloc(esme->read_len, "SMPP Rx");
if (!msg)
return -ENOMEM;