netdev - Re: [PATCH v3 bpf-next 2/6] bpf: udp: Make sure iter->batch always contains a full bucket snapshot

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: <aAGVV0JtJDMR1O0Z@t14>
Date: Thu, 17 Apr 2025 16:57:11 -0700
From: Jordan Rife <jordan@...fe.io>
To: Kuniyuki Iwashima <kuniyu@...zon.com>
Cc: aditi.ghag@...valent.com, bpf@...r.kernel.org, daniel@...earbox.net,
	martin.lau@...ux.dev, netdev@...r.kernel.org,
	willemdebruijn.kernel@...il.com
Subject: Re: [PATCH v3 bpf-next 2/6] bpf: udp: Make sure iter->batch always
 contains a full bucket snapshot

> > @@ -3454,15 +3460,26 @@ static struct sock *bpf_iter_udp_batch(struct seq_file *seq)
> >  				batch_sks++;
> >  			}
> >  		}
> > -		spin_unlock_bh(&hslot2->lock);
> >  
> >  		if (iter->end_sk)
> >  			break;
> > +next_bucket:
> > +		/* Somehow the bucket was emptied or all matching sockets were
> > +		 * removed while we held onto its lock. This should not happen.
> > +		 */
> > +		if (WARN_ON_ONCE(!resizes))
> > +			/* Best effort; reset the resize budget and move on. */
> > +			resizes = MAX_REALLOC_ATTEMPTS;
> > +		if (lock)
> > +			spin_unlock_bh(lock);
> > +		lock = NULL;
> >  	}
> >  
> >  	/* All done: no batch made. */
> >  	if (!iter->end_sk)
> > -		return NULL;
> > +		goto done;
> 
> If we jump here when no UDP socket exists, uninitialised sk is returned.
> Maybe move this condition down below the sk initialisation.

In this case, we'd want to return NULL just like it did before, since
there's no socket in the batch. Do you want me to make this more
explicit by setting sk = NULL here?

-Jordan