Re: [PATCH] selftests/seccomp: Accept any valid fd in user_notification_addfd

[Kees Cook <keescook@chromium.org>]

On Thu, Jan 28, 2021 at 10:17:21AM -0600, Seth Forshee wrote:
> This test expects fds to have specific values, which works fine
> when the test is run standalone. However, the kselftest runner
> consumes a couple of extra fds for redirection when running
> tests, so the test fails when run via kselftest.
> 
> Change the test to pass on any valid fd number.
> 
> Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

Thanks!

Acked-by: Kees Cook <keescook@chromium.org>

I'll snag this if Shuah doesn't first. :)

-Kees

> ---
>  tools/testing/selftests/seccomp/seccomp_bpf.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
> index 26c72f2b61b1..9338df6f4ca8 100644
> --- a/tools/testing/selftests/seccomp/seccomp_bpf.c
> +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
> @@ -4019,18 +4019,14 @@ TEST(user_notification_addfd)
>  
>  	/* Verify we can set an arbitrary remote fd */
>  	fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
> -	/*
> -	 * The child has fds 0(stdin), 1(stdout), 2(stderr), 3(memfd),
> -	 * 4(listener), so the newly allocated fd should be 5.
> -	 */
> -	EXPECT_EQ(fd, 5);
> +	EXPECT_GE(fd, 0);
>  	EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
>  
>  	/* Verify we can set an arbitrary remote fd with large size */
>  	memset(&big, 0x0, sizeof(big));
>  	big.addfd = addfd;
>  	fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big);
> -	EXPECT_EQ(fd, 6);
> +	EXPECT_GE(fd, 0);
>  
>  	/* Verify we can set a specific remote fd */
>  	addfd.newfd = 42;
> -- 
> 2.29.2
> 

-- 
Kees Cook