Subject: Re: [syzbot] [net?] [bpf?] possible deadlock in xsk_diag_dump

From: Jakub Kicinski <[email-masked]>
Date: Fri, 11 Apr 2025 15:38:22 -0700

On Tue, 08 Apr 2025 04:53:35 -0700 syzbot wrote:
> Chain exists of:
>   &xs->mutex --> &rdev->wiphy.mtx --> &net->xdp.lock
> 
>  Possible unsafe locking scenario:
> 
>        CPU0                    CPU1
>        ----                    ----
>   lock(&net->xdp.lock);
>                                lock(&rdev->wiphy.mtx);
>                                lock(&net->xdp.lock);
>   lock(&xs->mutex);

After looking at it with Stanislav our best guess is that we're mixing
normal and ops locked devices in close_many. Will send a fix over the
weekend.