net/http: limit chunked data overhead

The chunked transfer encoding adds some overhead to
the content transferred. When writing one byte per
chunk, for example, there are five bytes of overhead
per byte of data transferred: "1\r\nX\r\n" to send "X".

Chunks may include "chunk extensions",
which we skip over and do not use.
For example: "1;chunk extension here\r\nX\r\n".

A malicious sender can use chunk extensions to add
about 4k of overhead per byte of data.
(The maximum chunk header line size we will accept.)

Track the amount of overhead read in chunked data,
and produce an error if it seems excessive.

Fixes #64433
Fixes CVE-2023-39326

Change-Id: I40f8d70eb6f9575fb43f506eb19132ccedafcf39
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/2076135
Reviewed-by: Tatiana Bradley <tatianabradley@google.com>
Reviewed-by: Roland Shoemaker <bracewell@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/547335
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

0 files changed, 0 insertions, 0 deletions