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From:   Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [BUG] net: xfrm: possible null-pointer dereferences in xfrm_policy()
To:     steffen.klassert@secunet.com, herbert@gondor.apana.org.au,
        davem@davemloft.net
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Message-ID: <464bb93d-75b2-c21b-ee32-25a10ff61622@gmail.com>
Date:   Mon, 29 Jul 2019 11:43:49 +0800
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In xfrm_policy(), the while loop on lines 3802-3830 ends when dst->xfrm 
is NULL.
Then, dst->xfrm is used on line 3840:
     xfrm_state_mtu(dst->xfrm, mtu);
         if (x->km.state != XFRM_STATE_VALID...)
         aead = x->data;

Thus, possible null-pointer dereferences may occur.

These bugs are found by a static analysis tool STCheck written by us.

I do not know how to correctly fix these bugs, so I only report them.


Best wishes,
Jia-Ju Bai