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Hannes Frederic Sowa authored
In case multiple writes to a unix stream socket race we could end up in a situation where we pre-allocate a new skb for use in unix_stream_sendpage but have to free it again in the locked section because another skb has been appended meanwhile, which we must use. Accidentally we didn't clear the pointer after consuming it and so we touched freed memory while appending it to the sk_receive_queue. So, clear the pointer after consuming the skb. This bug has been found with syzkaller (http://github.com/google/syzkaller) by Dmitry Vyukov. Fixes: 869e7c62 ("net: af_unix: implement stream sendpage support") Reported-by:
Dmitry Vyukov <dvyukov@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by:
Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by:
Eric Dumazet <edumazet@google.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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