Re: [PATCH] net: ipv4: Fix uninitialized pointer warning in fnhe_remove_oldest

[Purva Yeshi]

On 18/04/25 10:33, David Ahern wrote:
> On 4/17/25 4:00 PM, Kuniyuki Iwashima wrote:
> > From: Purva Yeshi <purvayeshi550@xxxxxxxxx>
> > Date: Thu, 17 Apr 2025 15:11:26 +0530
> > > Fix Smatch-detected issue:
> > > net/ipv4/route.c:605 fnhe_remove_oldest() error:
> > > uninitialized symbol 'oldest_p'.
> > >
> > > Initialize oldest_p to NULL to avoid uninitialized pointer warning in
> > > fnhe_remove_oldest.
> >
> > How does it remain uninitialised ?
> >
> > update_or_create_fnhe() ensures the bucket is not empty before
> > calling fnhe_remove_oldest().
>
> agreed. Not the simplest logic, but I do not see how oldest_p can be
> unset after the loop.

Hi David,

The loop always sets oldest_p when the list has at least one entry, 
which the caller guarantees. Smatch doesn't catch that context, so it 
flags a false positive.

Best regards,
Purva