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Date:   Fri, 16 Jun 2023 12:06:00 +0200
From:   Simon Horman <simon.horman@corigine.com>
To:     Arnd Bergmann <arnd@kernel.org>
Cc:     Edward Cree <ecree.xilinx@gmail.com>,
        Martin Habets <habetsm.xilinx@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>,
        netdev@vger.kernel.org, linux-net-drivers@amd.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] sfc: fix uninitialized variable use
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References: <20230616090844.2677815-1-arnd@kernel.org>
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On Fri, Jun 16, 2023 at 11:08:18AM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The new efx_bind_neigh() function contains a broken code path when IPV6 is
> disabled:
> 
> drivers/net/ethernet/sfc/tc_encap_actions.c:144:7: error: variable 'n' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
>                 if (encap->type & EFX_ENCAP_FLAG_IPV6) {
>                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/net/ethernet/sfc/tc_encap_actions.c:184:8: note: uninitialized use occurs here
>                 if (!n) {
>                      ^
> drivers/net/ethernet/sfc/tc_encap_actions.c:144:3: note: remove the 'if' if its condition is always false
>                 if (encap->type & EFX_ENCAP_FLAG_IPV6) {
>                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/net/ethernet/sfc/tc_encap_actions.c:141:22: note: initialize the variable 'n' to silence this warning
>                 struct neighbour *n;
>                                    ^
>                                     = NULL
> 
> Change it to use the existing error handling path here.
> 
> Fixes: 7e5e7d800011a ("sfc: neighbour lookup for TC encap action offload")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Simon Horman <simon.horman@corigine.com>