Re: [PATCH] Re: WAN: new PPP code for generic HDLC

From: Krzysztof Halasa
Date: Wed Mar 12 2008 - 16:10:49 EST


Jan Engelhardt <jengelh@xxxxxxxxxxxxxxx> writes:

>>+ /* LCP only */
>>+ if (pid == PID_LCP)
>>+ switch (cp->code) {
>>+ case LCP_PROTO_REJ:
>>+ pid = ntohs(*(__be16*)skb->data);
>
> What if skb->data happens to be unaligned (can that even happen?)

It can't if the hdlc header is 32-bit aligned... however, I can now
see the above is buggy, skb->data doesn't point to the protocol
field. Unused code paths :-(

> -static const char *code_names[CP_CODES] = {"0", "ConfReq", "ConfAck",
> +static const char *const code_names[] = {"0", "ConfReq", "ConfAck",
> "ConfNak", "ConfRej", "TermReq",
> "TermAck", "CodeRej", "ProtoRej",
> "EchoReq", "EchoReply", "Discard"};

The explicit sizes are there as a prevention.
Thanks.
--
Krzysztof Halasa
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