From: Stefan Sperling <stsp@stsp.name>
Subject: Re: [PATCH] privsep.c: ignore closefrom() return value
To: Anna “CyberTailor” <cyber+misc@sysrq.in>
Cc: gameoftrees@openbsd.org
Date: Mon, 6 Dec 2021 11:54:13 +0100

On Mon, Dec 06, 2021 at 03:19:04PM +0500, Anna “CyberTailor” wrote:
> closefrom(2) is void on FreeBSD and libbsd, so its return value has to
> be ignored.
> 
> https://bugs.gentoo.org/828003
> ---
>  lib/privsep.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)

This patch should be applied to -portable only.

On OpenBSD there are failure conditions:

     closefrom() will fail if:

     [EBADF]		fd is greater than all open file descriptors.

     [EINTR]		An interrupt was received.

Especially EINTR seems important. It means closefrom was interrupted
and could not complete its task.

> diff --git a/lib/privsep.c b/lib/privsep.c
> index ca518be1..8f233724 100644
> --- a/lib/privsep.c
> +++ b/lib/privsep.c
> @@ -2766,10 +2766,8 @@ got_privsep_exec_child(int imsg_fds[2], const char *path, const char *repo_path)
>  		fprintf(stderr, "%s: %s\n", getprogname(), strerror(errno));
>  		_exit(1);
>  	}
> -	if (closefrom(GOT_IMSG_FD_CHILD + 1) == -1) {
> -		fprintf(stderr, "%s: %s\n", getprogname(), strerror(errno));
> -		_exit(1);
> -	}
> +
> +	closefrom(GOT_IMSG_FD_CHILD + 1);
>  
>  	if (execl(path, path, repo_path, (char *)NULL) == -1) {
>  		fprintf(stderr, "%s: %s: %s\n", getprogname(), path,
> -- 
> 2.34.1
> 
>