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Date: Tue, 12 Sep 2023 09:58:44 -0600
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Subject: Re: [PATCH net] fix null-deref in ipv4_link_failure
Content-Language: en-US
To: Kyle Zeng <zengyhkyle@gmail.com>, pabeni@redhat.com
Cc: vfedorenko@novek.ru, davem@davemloft.net, netdev@vger.kernel.org,
 ssuryaextr@gmail.com
References: <ZP/OjT62OGVxwa3t@westworld>
From: David Ahern <dsahern@kernel.org>
In-Reply-To: <ZP/OjT62OGVxwa3t@westworld>
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On 9/11/23 8:35 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.
> 
> Fixes: ed0de45 ("ipv4: recompile ip options in ipv4_link_failure")
> Suggested-by: David Ahern <dsahern@kernel.org>
> Signed-off-by: Kyle Zeng <zengyhkyle@gmail.com>
> Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
> Cc: Vadim Fedorenko <vfedorenko@novek.ru>
> ---
>  net/ipv4/route.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 

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