Re: [PATCH] [v2 netfilter-next] netfilter: nf_tables: fib warnings

From: Pablo Neira Ayuso
Date: Mon Oct 31 2016 - 10:17:24 EST


On Sat, Oct 29, 2016 at 01:26:12AM +0200, Florian Westphal wrote:
> Arnd Bergmann <arnd@xxxxxxxx> wrote:
> > The newly added nft fib code produces two warnings:
> >
> > net/ipv4/netfilter/nft_fib_ipv4.c: In function 'nft_fib4_eval':
> > net/ipv4/netfilter/nft_fib_ipv4.c:80:6: error: unused variable 'i' [-Werror=unused-variable]
> > net/ipv4/netfilter/nft_fib_ipv4.c: In function ânft_fib4_evalâ:
> > net/ipv4/netfilter/nft_fib_ipv4.c:137:6: error: âoifâ may be used uninitialized in this function [-Werror=maybe-uninitialized]
> >
> > The first one is obvious as the only user of that variable is
> > inside of an #ifdef
> >
> > The second one is a bit trickier. It's clear that oif is in fact
> > uninitialized when it gets used when neither NFTA_FIB_F_IIF nor
> > NFTA_FIB_F_OIF are set, and just setting it to NULL won't work
> > as it may later get dereferenced.
> >
> > However, there is no need to search the result list if it is
> > NULL, as Florian pointed out. This integrates his (untested)
> > change to do so. I have confirmed that the combined patch
> > solves both warnings, but as I don't fully understand Florian's
> > change, I can't tell if it's correct.
> >
> > Suggested-by: Florian Westphal <fw@xxxxxxxxx>
> > Fixes: 84f5eedb983e ("netfilter: nf_tables: add fib expression")
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
[...]
> Tested-by: Florian Westphal <fw@xxxxxxxxx>

Applied, thanks!