[LTP] [PATCH] vsock01, CVE-2021-26708: Add reproducer for race condition

[Cyril Hrubis <chrubis@suse.cz>]

Hi!
> diff --git a/include/lapi/vm_sockets.h b/include/lapi/vm_sockets.h
> new file mode 100644
> index 000000000..94d0248c5
> --- /dev/null
> +++ b/include/lapi/vm_sockets.h
> @@ -0,0 +1,14 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2021 SUSE LLC <rpalethorpe@suse.com>
> + */
> +
> +#include <sys/socket.h>
> +
> +#if HAVE_LINUX_VM_SOCKETS_H
> +#  include <linux/vm_sockets.h>
> +#endif
> +
> +#ifndef VMADDR_CID_LOCAL
> +#  define VMADDR_CID_LOCAL 1
> +#endif

I've added guards to this header.

> +#include "config.h"
> +#include "tst_test.h"
> +
> +#if HAVE_LINUX_VM_SOCKETS_H
> +#  include "tst_fuzzy_sync.h"
> +#  include "lapi/vm_sockets.h"
> +
> +static struct tst_fzsync_pair pair;
> +int vsock = -1;
> +
> +void *writer(LTP_ATTRIBUTE_UNUSED void *unused)
> +{
> +	const uint64_t b_buflen = 0x4141;
> +
> +	while (tst_fzsync_run_b(&pair)) {
> +		tst_fzsync_start_race_b(&pair);
> +		SAFE_SETSOCKOPT(vsock, AF_VSOCK,
> +				SO_VM_SOCKETS_BUFFER_SIZE,
> +				&b_buflen, sizeof(b_buflen));
> +		tst_fzsync_end_race_b(&pair);
> +	}
> +
> +
> +	return NULL;
> +}

And sprinkled a few 'static' keywords here, and pushed, thanks.

-- 
Cyril Hrubis
chrubis@suse.cz