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From:   Qingfang DENG <dqfext@gmail.com>
To:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>,
        Masahide NAKAMURA <nakam@linux-ipv6.org>,
        Ville Nuorvala <vnuorval@tcs.hut.fi>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Qingfang DENG <qingfang.deng@siflower.com.cn>
Subject: [PATCH net v2] neighbour: fix unaligned access to pneigh_entry
Date:   Thu,  1 Jun 2023 09:54:32 +0800
Message-Id: <20230601015432.159066-1-dqfext@gmail.com>
In-Reply-To: <CANn89iKRX2QTgS44Ky6Jua-+UNrFY3E7RCT_7OfG=GnFvAzdFQ@mail.gmail.com>
References: <CANn89iKRX2QTgS44Ky6Jua-+UNrFY3E7RCT_7OfG=GnFvAzdFQ@mail.gmail.com>
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From: Qingfang DENG <qingfang.deng@siflower.com.cn>

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>
---
v2: remove the ifdef, and use u32 type

 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 3fa5774bddac..f6a8ecc6b1fa 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -180,7 +180,7 @@ struct pneigh_entry {
 	netdevice_tracker	dev_tracker;
 	u32			flags;
 	u8			protocol;
-	u8			key[];
+	u32			key[];
 };
 
 /*
-- 
2.34.1