[release-branch.go1.18] encoding/pem: fix stack overflow in Decode
Previously, Decode called decodeError, a recursive function that was
prone to stack overflows when given a large PEM file containing errors.
Credit to Juho Nurminen of Mattermost who reported the error.
Fixes CVE-2022-24675
Updates #51853
Fixes #52037
Change-Id: Iffe768be53c8ddc0036fea0671d290f8f797692c
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/
1391157
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Filippo Valsorda <valsorda@google.com>
(cherry picked from commit
794ea5e828010e8b68493b2fc6d2963263195a02)
Reviewed-on: https://go-review.googlesource.com/c/go/+/399817
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>