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| author | Guillaume Nault <g.nault@alphalink.fr> | 2014-01-16 21:23:58 +0100 |
|---|---|---|
| committer | Dmitry Kozlov <xeb@mail.ru> | 2014-02-08 09:45:39 +0400 |
| commit | 0e63419ea36db3a8d673997f1ff74309b9cb77f2 (patch) | |
| tree | 95aea6347c03fee715d86cadfc1dd3cd9d9b4867 | |
| parent | 65be5ebef989e62091368c7457ad33f1e8d63ead (diff) | |
| download | accel-ppp-0e63419ea36db3a8d673997f1ff74309b9cb77f2.tar.gz accel-ppp-0e63419ea36db3a8d673997f1ff74309b9cb77f2.zip | |
pppoe: check for tag format validity in PADR messages
Avoid parsing inconsistent PPPoE tags when handling PADR.
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
| -rw-r--r-- | accel-pppd/ctrl/pppoe/pppoe.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/accel-pppd/ctrl/pppoe/pppoe.c b/accel-pppd/ctrl/pppoe/pppoe.c index a272dc0a..56436ef6 100644 --- a/accel-pppd/ctrl/pppoe/pppoe.c +++ b/accel-pppd/ctrl/pppoe/pppoe.c @@ -921,6 +921,17 @@ static void pppoe_recv_PADR(struct pppoe_serv_t *serv, uint8_t *pack, int size) for (n = 0; n < ntohs(hdr->length); n += sizeof(*tag) + ntohs(tag->tag_len)) { tag = (struct pppoe_tag *)(pack + ETH_HLEN + sizeof(*hdr) + n); + + if (n + sizeof(*tag) > ntohs(hdr->length)) { + if (conf_verbose) + log_warn("pppoe: discard PADR packet (truncated tag)\n"); + return; + } + if (n + sizeof(*tag) + ntohs(tag->tag_len) > ntohs(hdr->length)) { + if (conf_verbose) + log_warn("pppoe: discard PADR packet (invalid tag length)\n"); + return; + } switch (ntohs(tag->tag_type)) { case TAG_END_OF_LIST: break; |