Messages in this thread | | | Date | Sun, 2 Apr 2017 13:45:45 +0200 | From | Florian Westphal <> | Subject | Re: KASAN, xt_TCPMSS finally found nasty use-after-free bug? 4.10.8 |
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Eric Dumazet <eric.dumazet@gmail.com> wrote: > - for (i = sizeof(struct tcphdr); i <= tcp_hdrlen - TCPOLEN_MSS; i += optlen(opt, i)) { > + for (i = sizeof(struct tcphdr); i < tcp_hdrlen - TCPOLEN_MSS; i += optlen(opt, i)) { > if (opt[i] == TCPOPT_MSS && opt[i+1] == TCPOLEN_MSS) { > u_int16_t oldmss;
maybe I am low on caffeeine but this looks fine, for tcp header with only tcpmss this boils down to "20 <= 24 - 4" so we acccess offsets 20-23 which seems ok.
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