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Date: Sun, 10 Sep 2023 22:36:01 -0600
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Subject: Re: [PATCH net] fix null-deref in ipv4_link_failure
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To: Kyle Zeng <zengyhkyle@gmail.com>, pabeni@redhat.com
Cc: davem@davemloft.net, netdev@vger.kernel.org, ssuryaextr@gmail.com
References: <ZPqSfGGAwa1I69Sm@westworld>
From: David Ahern <dsahern@kernel.org>
In-Reply-To: <ZPqSfGGAwa1I69Sm@westworld>
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On 9/7/23 9:18 PM, Kyle Zeng wrote:
> Currently, we assume the skb is associated with a device before calling
> __ip_options_compile, which is not always the case if it is re-routed by
> ipvs.
> When skb->dev is NULL, dev_net(skb->dev) will become null-dereference.
> This patch adds a check for the edge case and switch to use the net_device
> from the rtable when skb->dev is NULL.
> 
> Suggested-by: Paolo Abeni<pabeni@redhat.com>
> Suggested-by: David Ahern <dsahern@kernel.org>
> Signed-off-by: Kyle Zeng <zengyhkyle@gmail.com>
> Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
> ---
>  net/ipv4/route.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 

Reviewed-by: David Ahern <dsahern@kernel.org>