From: Oleg Nesterov <oleg@redhat.com>
To: Eugene Syromiatnikov <esyr@redhat.com>
Cc: linux-kernel@vger.kernel.org,
Christian Brauner <christian@brauner.io>,
Andrew Morton <akpm@linux-foundation.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
"Dmitry V. Levin" <ldv@altlinux.org>,
Eric Biederman <ebiederm@xmission.com>
Subject: Re: [PATCH] fork: fail on non-zero higher 32 bits of args.exit_signal
Date: Tue, 10 Sep 2019 14:44:41 +0200 [thread overview]
Message-ID: <20190910124440.GA25647@redhat.com> (raw)
In-Reply-To: <20190910115711.GA3755@asgard.redhat.com>
On 09/10, Eugene Syromiatnikov wrote:
>
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -2562,6 +2562,9 @@ noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
> if (copy_from_user(&args, uargs, size))
> return -EFAULT;
>
> + if (unlikely(((unsigned int)args.exit_signal) != args.exit_signal))
> + return -EINVAL;
Hmm. Unless I am totally confused you found a serious bug...
Without CLONE_THREAD/CLONE_PARENT copy_process() blindly does
p->exit_signal = args->exit_signal;
the valid_signal(sig) check in do_notify_parent() mostly saves us, but we
must not allow child->exit_signal < 0, if nothing else this breaks
thread_group_leader().
And afaics this patch doesn't fix this? I think we need the valid_signal()
check...
Oleg.
next prev parent reply other threads:[~2019-09-10 12:44 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-10 11:57 [PATCH] fork: fail on non-zero higher 32 bits of args.exit_signal Eugene Syromiatnikov
2019-09-10 12:20 ` Dmitry V. Levin
2019-09-10 12:44 ` Oleg Nesterov [this message]
2019-09-10 13:09 ` Christian Brauner
2019-09-10 13:10 ` Christian Brauner
2019-09-10 13:27 ` Christian Brauner
2019-09-10 14:27 ` Eugene Syromiatnikov
2019-09-10 14:39 ` Oleg Nesterov
2019-09-10 14:46 ` Christian Brauner
2019-09-10 15:18 ` Eugene Syromiatnikov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190910124440.GA25647@redhat.com \
--to=oleg@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=christian@brauner.io \
--cc=ebiederm@xmission.com \
--cc=esyr@redhat.com \
--cc=ldv@altlinux.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox