cmd/go: disallow package directories containing newlines

Directory or file paths containing newlines may cause tools (such as
cmd/cgo) that emit "//line" or "#line" -directives to write part of
the path into non-comment lines in generated source code. If those
lines contain valid Go code, it may be injected into the resulting
binary.

(Note that Go import paths and file paths within module zip files
already could not contain newlines.)

Thanks to Juho Nurminen of Mattermost for reporting this issue.

Fixes #60167.
Fixes CVE-2023-29402.

Change-Id: I64572e9f454bce7b685d00e2e6a1c96cd33d53df
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1882606
Reviewed-by: Roland Shoemaker <bracewell@google.com>
Run-TryBot: Roland Shoemaker <bracewell@google.com>
Reviewed-by: Russ Cox <rsc@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/501226
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

0 files changed, 0 insertions, 0 deletions