From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net] sctp: check af before verify address in
 sctp_addr_id2transport
Date: Tue, 07 Feb 2017 14:08:46 -0500 (EST)
Message-ID: <20170207.140846.1728839010237371851.davem@davemloft.net>
References: <d4c232a9f69f9eae6537f74078dc0d2a0574e8eb.1486472168.git.lucien.xin@gmail.com>
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        marcelo.leitner@gmail.com, nhorman@tuxdriver.com,
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To: lucien.xin@gmail.com
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From: Xin Long <lucien.xin@gmail.com>
Date: Tue,  7 Feb 2017 20:56:08 +0800

> Commit 6f29a1306131 ("sctp: sctp_addr_id2transport should verify the
> addr before looking up assoc") invoked sctp_verify_addr to verify the
> addr.
> 
> But it didn't check af variable beforehand, once users pass an address
> with family = 0 through sockopt, sctp_get_af_specific will return NULL
> and NULL pointer dereference will be caused by af->sockaddr_len.
> 
> This patch is to fix it by returning NULL if af variable is NULL.
> 
> Fixes: 6f29a1306131 ("sctp: sctp_addr_id2transport should verify the addr before looking up assoc")
> Signed-off-by: Xin Long <lucien.xin@gmail.com>

Applied, thank you.