linux-kernel - Re: [PATCH 2/2] exec: Make do_coredump more robust and safer when using pipes in core

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: <20090626164819.GA12063@redhat.com>
Date:	Fri, 26 Jun 2009 18:48:19 +0200
From:	Oleg Nesterov <oleg@...hat.com>
To:	Neil Horman <nhorman@...driver.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org, earl_chew@...lent.com,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	Andi Kleen <andi@...stfloor.org>
Subject: Re: [PATCH 2/2] exec: Make do_coredump more robust and safer when
	using pipes in core_pattern: wait for core collectors

On 06/26, Neil Horman wrote:
>
> - 		if (call_usermodehelper_pipe(corename+1, helper_argv, NULL,
> -				&file)) {
> + 		if (call_usermodehelper_pipe(helper_argv[0], helper_argv, NULL,
> +				&file, &pid) < 0) {

...


> +	if (ispipe && core_pipe_limit)
> +		sys_wait4(pid, NULL, 0, NULL);

How this can work? sys_wait4() can only wait for our childs, but the parent
of the dumping thread is khelper.


If we change kmod.c, then I think we need UMH_WAIT_CUSTOM_COMPLETION.


But perhaps do_coredump() can just sleep on file->...->i_pipe->wait waiting
for pipe_inode_info->readers == 0 ?

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/