Both gcc and clang accept an option -fplugin=code.so to load
a plugin from the ELF shared object file code.so.
Obviously that plugin can then do anything it wants
during the build. This is contrary to the goal of "go get"
never running untrusted code during the build.
(What happens if you choose to run the result of
the build is your responsibility.)
Disallow this behavior by only allowing a small set of
known command-line flags in #cgo CFLAGS directives
(and #cgo LDFLAGS, etc).
The new restrictions can be adjusted by the environment
variables CGO_CFLAGS_ALLOW, CGO_CFLAGS_DISALLOW,
and so on. See the documentation.
In addition to excluding cgo-defined flags, we also have to
make sure that when we pass file names on the command
line, they don't look like flags. So we now refuse to build
packages containing suspicious file names like -x.go.
A wrinkle in all this is that GNU binutils uniformly accept
@foo on the command line to mean "if the file foo exists,
then substitute its contents for @foo in the command line".
So we must also reject @x.go, flags and flag arguments
beginning with @, and so on.
Fixes#23672, CVE-2018-6574.
Change-Id: I59e7c1355155c335a5c5ae0d2cf8fa7aa313940a
Reviewed-on: https://team-review.git.corp.google.com/209949
Reviewed-by: Ian Lance Taylor <iant@google.com>
rune has a well-defined size, but C.int is implementation-specified.
Using one as the other should require an explicit conversion.
updates #13467
Change-Id: I53ab2478427dca790efdcc197f6b8d9fbfbd1847
Reviewed-on: https://go-review.googlesource.com/63730
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This makes the test easier to run in isolation and easier to change,
and simplifies the code to run the tests in parallel.
updates #13467
Change-Id: I5622b5cc98276970347da18e95d071dbca3c5cc1
Reviewed-on: https://go-review.googlesource.com/63276
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
