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Fix nsupdate hang when processing a large update

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The root cause is the fix for CVE-2024-0760 (part 3), which resets
the TCP connection on a failed send. Specifically commit
4b7c6138 stops reading on the socket
because the TCP connection is throttling.

When the tcpdns_send_cb callback thinks about restarting reading
on the socket, this fails because the socket is a client socket.
And nsupdate is a client and is using the same netmgr code.

This commit removes the requirement that the socket must be a server
socket, allowing reading on the socket again after being throttled.

(manually picked from commit aa24b77d8b)
This commit is contained in:
Matthijs Mekking 2024-12-06 09:45:46 +01:00
parent 7068d0698f
commit 90fbe91997
2 changed files with 22 additions and 11 deletions
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14
lib/isc/netmgr/tcpdns.c
View file

@ -1269,12 +1269,18 @@ isc__nm_async_tcpdnssend(isc__networker_t *worker, isc__netievent_t *ev0) {
goto fail;
}
if (!sock->client && sock->reading) {
sock->reading_throttled = true;
isc__nm_stop_reading(sock);
}
isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL, ISC_LOGMODULE_NETMGR,
ISC_LOG_DEBUG(3),
"throttling TCP connection, the other side is not "
"reading the data, switching to uv_write()");
sock->reading_throttled = true;
isc__nm_stop_reading(sock);
"%sthe other side is not "
"reading the data, switching to uv_write()",
!sock->client && sock->reading
? "throttling TCP connection, "
: "");
r = uv_write(&uvreq->uv_req.write, &sock->uv_handle.stream, bufs, nbufs,
tcpdns_send_cb);

19
lib/isc/netmgr/tlsdns.c
View file

@ -1377,13 +1377,18 @@ tls_cycle_output(isc_nmsocket_t *sock) {
break;
}
isc_log_write(
isc_lctx, ISC_LOGCATEGORY_GENERAL, ISC_LOGMODULE_NETMGR,
ISC_LOG_DEBUG(3),
"throttling TCP connection, the other side is not "
"reading the data, switching to uv_write()");
sock->reading_throttled = true;
isc__nm_stop_reading(sock);
if (!sock->client && sock->reading) {
sock->reading_throttled = true;
isc__nm_stop_reading(sock);
}
isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
ISC_LOGMODULE_NETMGR, ISC_LOG_DEBUG(3),
"%sthe other side is not "
"reading the data, switching to uv_write()",
!sock->client && sock->reading
? "throttling TCP connection, "
: "");
r = uv_write(&req->uv_req.write, &sock->uv_handle.stream,
&req->uvbuf, 1, tls_write_cb);