linux-kernel - Re: [REGRESSION] af_unix: Introduce SO_PASSRIGHTS

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: <b5628073-3d14-42a9-9b91-3ec31db8f7f9@heusel.eu>
Date: Wed, 11 Jun 2025 19:10:24 +0200
From: Christian Heusel <christian@...sel.eu>
To: Kuniyuki Iwashima <kuni1840@...il.com>
Cc: davem@...emloft.net, difrost.kernel@...il.com, dnaim@...hyos.org, 
	edumazet@...gle.com, horms@...nel.org, kuba@...nel.org, kuniyu@...zon.com, 
	linux-kernel@...r.kernel.org, mario.limonciello@....com, netdev@...r.kernel.org, 
	pabeni@...hat.com, regressions@...ts.linux.dev
Subject: Re: [REGRESSION] af_unix: Introduce SO_PASSRIGHTS - break OpenGL

On 25/06/11 09:42AM, Kuniyuki Iwashima wrote:
> From: Christian Heusel <christian@...sel.eu>
> Date: Wed, 11 Jun 2025 13:46:01 +0200
> > On 25/06/10 09:22PM, Jacek Łuczak wrote:
> > > Hi,
> > 
> > Hey,
> > 
> > > Bisection points to:
> > > [3f84d577b79d2fce8221244f2509734940609ca6] af_unix: Inherit sk_flags
> > > at connect().
> > 
> > I'm also suffering from an issue that I have bisected to the same commit,
> > although in a totally different environment and with other reproduction
> > steps: For me the Xorg server crashes as soon as I re-plug my laptops
> > power chord and afterwards I can only switch to a TTY to debug. No
> > errors are logged in the dmesg.
> > 
> > I can also confirm that reverting the patch on top of 6.16-rc1 fixes the
> > issue for me (thanks for coming up with the revert to Naim from the
> > CachyOS team!).
> > 
> > My xorg version is 21.1.16-1 on Arch Linux and I have attached the
> > revert, my xorg log from the crash and bisection log to this mail!
> > 
> > I'll also CC a few of the netdev people that might have further insights
> > for this issue!
> > 
> > > Reverting entire SO_PASSRIGHTS fixes the issue.
> 
> Thanks for the report.
> 
> Could you test the diff below ?

It seems like the patch you posted has fixed the issue for me, thanks
for the lightning-fast answer!

> look like some programs start listen()ing before setting
> SO_PASSCRED or SO_PASSPIDFD and there's a small race window.
> 
> ---8<---
> diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
> index fd6b5e17f6c4..87439d7f965d 100644
> --- a/net/unix/af_unix.c
> +++ b/net/unix/af_unix.c
> @@ -1971,7 +1971,8 @@ static void unix_maybe_add_creds(struct sk_buff *skb, const struct sock *sk,
>  	if (UNIXCB(skb).pid)
>  		return;
>  
> -	if (unix_may_passcred(sk) || unix_may_passcred(other)) {
> +	if (unix_may_passcred(sk) || unix_may_passcred(other) ||
> +	    !other->sk_socket) {
>  		UNIXCB(skb).pid = get_pid(task_tgid(current));
>  		current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid);
>  	}
> ---8<---

Have a great week everyone!
Chris

Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)