tree ed86dd7febd2f50ebc492af8ad85f9a7bd1e4db4
parent db4efeb81f4bf3cc8fc2e2beaf2af9c7f7bebaad
author Damien Neil <dneil@google.com> 1638829903 -0800
committer Filippo Valsorda <filippo@golang.org> 1639054153 +0000

http2: cap the size of the server's canonical header cache

The HTTP/2 server keeps a per-connection cache mapping header keys
to their canonicalized form (e.g., "foo-bar" => "Foo-Bar"). Cap the
maximum size of this cache to prevent a peer sending many unique
header keys from causing unbounded memory growth.

Cap chosen arbitrarily at 32 entries. Since this cache does not
include common headers (e.g., "content-type"), 32 seems like more
than enough for almost all normal uses.

Fixes #50058
Fixes CVE-2021-44716

Change-Id: Ia83696dc23253c12af8f26d502557c2cc9841105
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1290827
Reviewed-by: Roland Shoemaker <bracewell@google.com>
Reviewed-on: https://go-review.googlesource.com/c/net/+/369794
Trust: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Trust: Damien Neil <dneil@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>