tree 595407771a9cd167722793eebf78a798abc3bb55
parent ca1201d0de80cfde86cb01aea620983605dfe99b
author Filippo Valsorda <filippo@golang.org> 1565503938 -0400
committer Filippo Valsorda <filippo@golang.org> 1565705583 -0400

http2: limit number of control frames in server send queue

An attacker could cause servers to queue an unlimited number of PING
ACKs or RST_STREAM frames by soliciting them and not reading them, until
the program runs out of memory.

Limit control frames in the queue to a few thousands (matching the limit
imposed by other vendors) by counting as they enter and exit the scheduler,
so the protection will work with any WriteScheduler.

Once the limit is exceeded, close the connection, as we have no way to
communicate with the peer.

This addresses CVE-2019-9512 and CVE-2019-9514.

Fixes golang/go#33606

Change-Id: I842968fc6ed3eac654b497ade8cea86f7267886b
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/525552
Reviewed-by: Brad Fitzpatrick <bradfitz@google.com>