BUG/MEDIUM: quic: Possible crashes when sending too short Initial packets

This may happen during handshakes when Handshake packets cannot be coalesced
to a first Initial packet because of TX frame allocation failures (from
qc_build_frms()). This leads too short (not padded) Initial packets to be sent.
This is detected by a BUG_ON() in qc_send_ppkts().

To avoid this an Handshake packet without ack-eliciting frames which should have
been built by qc_build_frms() is built.

Must be backported as far as 2.6.
This commit is contained in:
Frédéric Lécaille 2023-11-07 18:29:28 +01:00
parent c78cb49a3b
commit b21e08cbd2

View File

@ -2283,11 +2283,17 @@ static int qc_do_build_pkt(unsigned char *pos, const unsigned char *end,
end - pos, &len_frms, pos - beg, qel, qc)) {
TRACE_PROTO("Not enough room", QUIC_EV_CONN_TXPKT,
qc, NULL, NULL, &room);
if (padding) {
len_frms = 0;
goto comp_pkt_len;
}
if (!ack_frm_len && !qel->pktns->tx.pto_probe)
goto no_room;
}
}
comp_pkt_len:
/* Length (of the remaining data). Must not fail because, the buffer size
* has been checked above. Note that we have reserved QUIC_TLS_TAG_LEN bytes
* for the encryption tag. It must be taken into an account for the length