Messages in this thread | | | From | Sabyrzhan Tasbolatov <> | Subject | Re: [PATCH] net/qrtr: restrict length in qrtr_tun_write_iter() | Date | Sun, 21 Feb 2021 18:39:12 +0600 |
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> Do we really expect to accept huge lengths here ?
Sorry for late response but I couldnt find any reference to the max length of incoming data for qrtr TUN interface.
> qrtr_endpoint_post() will later attempt a netdev_alloc_skb() which will need > some extra space (for struct skb_shared_info)
Thanks, you're right, qrtr_endpoint_post() will alloc another slab buffer. We can check the length of skb allocation but we need to do following:
int qrtr_endpoint_post(.., const void *data, size_t len) { .. when QRTR_PROTO_VER_1: hdrlen = sizeof(*data); when QRTR_PROTO_VER_2: hdrlen = sizeof(*data) + data->optlen; len = (KMALLOC_MAX_SIZE - hdrlen) % data->size; skb = netdev_alloc_skb(NULL, len); .. skb_put_data(skb, data + hdrlen, size);
So it requires refactoring as in qrtr_tun_write_iter() we just allocate and pass it to qrtr_endpoint_post() and there we need to do len calculation as above *before* netdev_alloc_skb(NULL, len).
Perhaps there is a nicer solution though.
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