From: samuel@...
Date: 2021-08-06T22:12:31+00:00
Subject: [ruby-core:104815] [Ruby master Bug#18061] Execshield test: libruby.so.N.N.N: FAIL: property-note test because no .note.gnu.property section found

Issue #18061 has been updated by ioquatix (Samuel Williams).


```
On another side, we have an Intel CET [2], [3]:
"Control-flow Enforcement Technology (CET) provides the following capabilities to defend
against ROP/JOP style control-flow subversion attacks:
- Shadow Stack - return address protection to defend against Return Oriented Programming,
- Indirect branch tracking - free branch protection to defend against Jump/Call Oriented Programming.���"

Intel CET uses following processor-specific program property types in .note.gnu.property [3, p85, p87]:

* GNU_PROPERTY_X86_FEATURE_1_IBT This indicates that all executable sections are compatible
with IBT (see Section 13.1.1) when endbr64 instruction starts each valid target where an indirect
branch instruction can land. 8
* GNU_PROPERTY_X86_FEATURE_1_SHSTK This indicates that all executable sections are compatible
with SHSTK (see Section 13.1.2) where return address popped from shadow stack always matches
return address popped from normal stack.
```

We should confirm that coroutine stack swapping is compatible with `GNU_PROPERTY_X86_FEATURE_1_SHSTK`.

----------------------------------------
Bug #18061:  Execshield test: libruby.so.N.N.N: FAIL: property-note test because no .note.gnu.property section found
https://bugs.ruby-lang.org/issues/18061#change-93157

* Author: jaruga (Jun Aruga)
* Status: Open
* Priority: Normal
* Backport: 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN
----------------------------------------
I found an issue in our company's internal test called "execshield" by a security tool annobin - annocheck command [1][2].

```
Hardened: libruby.so.2.7.4: FAIL: property-note test because no .note.gnu.property section found
```

Here is the reproducer on the upstream latest master, commit is 5f2987d6c2ae9ace3178ac3e1bbb4ac7079101eb,

```
$ autoconf
$ ./configure --enable-shared
$ make

$ ls libruby.so.3.1.0
libruby.so.3.1.0*
```

If you are using Red Hat based Linux distro, it's easy to install by the RPM package like this.

```
$ sudo dnf -y install annobin-annocheck
```

```
$ sudo yum -y install annobin-annocheck
```

Then

```
$ annocheck libruby.so.3.1.0
```

If you are using other Linux distros such as Ubuntu, you can use it by a container I prepared.

Prepare the following `Dockerfile`.

```
$ cat Dockerfile 
FROM docker.io/fedora:34

RUN cat /etc/fedora-release
RUN dnf -y install annobin-annocheck
WORKDIR /work
```

Then build the container image with the `Dockerfile` and run the annocheck command for the `libruby.so.3.1.0` on your host environment. The `-v` is an option for bind mount between host and container environment.

```
$ docker build --rm -t fedora-annocheck .

$ docker run --rm -t -v $(pwd):/work fedora-annocheck annocheck /work/libruby.so.3.1.0
annocheck: Version 9.79.
Hardened: libruby.so.3.1.0: FAIL: bind-now test because not linked with -Wl,-z,now 
Hardened: libruby.so.3.1.0: FAIL: notes test because gaps were detected in the annobin coverage 
Hardened: libruby.so.3.1.0: FAIL: cf-protection test because no .note.gnu.property section = no control flow information 
Hardened: libruby.so.3.1.0: FAIL: property-note test because no .note.gnu.property section found 
Hardened: Rerun annocheck with --verbose to see more information on the tests.
```

The message `Hardened: libruby.so.3.1.0: FAIL: property-note test because no .note.gnu.property section found` is what I found in our internal test. For other FAIL messages, maybe it can be fixed by changing how to build.

Asking a colleague, I was told that the `coroutine/*/Context.S` files such as [coroutine/x86/Context.S](https://github.com/ruby/ruby/blob/master/coroutine/x86/Context.S) cause the failure. Do you have any idea how to fix this? Thanks.

* [1] https://sourceware.org/annobin/
* [2] You can see `man annocheck` or https://www.mankier.com/1/annocheck .

---Files--------------------------------
0001-Add-.note.gnu.property-sections.patch (2.64 KB)
0001-Add-.note.gnu.property-sections.patch (3.69 KB)


-- 
https://bugs.ruby-lang.org/

Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>