Re: [PATCH net v2] eth: fbnic: fix double-free of PCS on phylink creation failure

[Jakub Kicinski]

On Thu, 7 May 2026 12:34:24 +0200 Paolo Abeni wrote:
> > Clearing fbd->netdev to NULL avoids UAF in init_failure_mode where
> > callers guard by checking !fbd->netdev, such as fbnic_mdio_read_pmd().
> > These callers remain active even after a failed probe, so fdb->netdev
> > still needs to be cleared.
> > 
> > Fixes: d0fe7104c795 ("fbnic: Replace use of internal PCS w/ Designware XPCS")
> > Signed-off-by: Bobby Eshleman <bobbyeshleman@xxxxxxxx>  
> 
> Note that sashiko-gemini spotted a pre-existing issue:
> 
> https://sashiko.dev/#/patchset/20260504-fbnic-pcs-fix-v2-1-de45192821d9%40meta.com
> 
> does not block this patch but could deserve a follow-up.

fbd is a devlink priv, not netdev priv, touching it after free_netdev()
is perfectly fine. I wish Gemini tried a *little* harder instead of
guessing :| Sorry for not commenting earlier.