Received-SPF: pass (google.com: domain of linux-kernel+bounces-211630-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
Feedback-ID: i787e41f1:Fastmail
Date: Wed, 12 Jun 2024 15:59:39 +0200
From: Greg KH <greg@kroah.com>
To: Qingfang Deng <dqfext@gmail.com>
Cc: stable@vger.kernel.org, Qingfang Deng <qingfang.deng@siflower.com.cn>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Masahide NAKAMURA <nakam@linux-ipv6.org>,
	YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>,
	Ville Nuorvala <vnuorval@tcs.hut.fi>, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 4.19.y] neighbour: fix unaligned access to pneigh_entry
Message-ID: <2024061231-most-blinker-c31c@gregkh>
References: <20240605022916.247882-1-dqfext@gmail.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20240605022916.247882-1-dqfext@gmail.com>

On Wed, Jun 05, 2024 at 10:29:16AM +0800, Qingfang Deng wrote:
> From: Qingfang Deng <qingfang.deng@siflower.com.cn>
> 
> [ Upstream commit ed779fe4c9b5a20b4ab4fd6f3e19807445bb78c7 ]
> 
> After the blamed commit, the member key is longer 4-byte aligned. On
> platforms that do not support unaligned access, e.g., MIPS32R2 with
> unaligned_action set to 1, this will trigger a crash when accessing
> an IPv6 pneigh_entry, as the key is cast to an in6_addr pointer.
> 
> Change the type of the key to u32 to make it aligned.
> 
> Fixes: 62dd93181aaa ("[IPV6] NDISC: Set per-entry is_router flag in Proxy NA.")
> Signed-off-by: Qingfang Deng <qingfang.deng@siflower.com.cn>
> ---
>  include/net/neighbour.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/net/neighbour.h b/include/net/neighbour.h
> index e58ef9e338de..4c53e51f0799 100644
> --- a/include/net/neighbour.h
> +++ b/include/net/neighbour.h
> @@ -172,7 +172,7 @@ struct pneigh_entry {
>  	possible_net_t		net;
>  	struct net_device	*dev;
>  	u8			flags;
> -	u8			key[0];
> +	u32			key[0];
>  };
>  
>  /*
> -- 
> 2.34.1
> 
> 

Now queued up, thanks.

greg k-h