linux-kernel - Re: [PATCH 1/2] fs, close_range: add flag CLOSE_RANGE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20201013210925.GJ3576660@ZenIV.linux.org.uk>
Date:   Tue, 13 Oct 2020 22:09:25 +0100
From:   Al Viro <viro@...iv.linux.org.uk>
To:     Giuseppe Scrivano <gscrivan@...hat.com>
Cc:     linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        christian.brauner@...ntu.com, containers@...ts.linux-foundation.org
Subject: Re: [PATCH 1/2] fs, close_range: add flag CLOSE_RANGE_CLOEXEC

On Tue, Oct 13, 2020 at 04:06:08PM +0200, Giuseppe Scrivano wrote:
> +		spin_lock(&cur_fds->file_lock);
> +		fdt = files_fdtable(cur_fds);
> +		cur_max = fdt->max_fds - 1;
> +		max_fd = min(max_fd, cur_max);
> +		while (fd <= max_fd)
> +			__set_close_on_exec(fd++, fdt);
> +		spin_unlock(&cur_fds->file_lock);

	First of all, this is an atrocious way to set all bits
in a range.  What's more, you don't want to set it for *all*
bits - only for the ones present in open bitmap.  It's probably
harmless at the moment, but let's not create interesting surprises
for the future.