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| author | Tobias Klauser <tklauser@distanz.ch> | 2016-08-03 10:31:46 +0200 |
|---|---|---|
| committer | Tobias Klauser <tklauser@distanz.ch> | 2016-08-03 10:31:46 +0200 |
| commit | c36d446a9b5b3b6a8b8d4f57c65c319c66968310 (patch) | |
| tree | d8ae2c316e89a3177440be1f77c0933475ca7f60 | |
| parent | 5939d09f16547ab935d8e3699688ed1817471da5 (diff) | |
llmnr-query: Prevent read buffer overflow in response parsing
When accessing the compressed name in a response, verify that the
pointer is within the packet size.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
| -rw-r--r-- | llmnr-query.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/llmnr-query.c b/llmnr-query.c index fefcf0b..27a2034 100644 --- a/llmnr-query.c +++ b/llmnr-query.c @@ -306,9 +306,13 @@ int main(int argc, char **argv) /* compression? */ if (nl & 0xC0) { uint16_t ptr = (nl & 0x3F) << 8 | *pkt_put(p, 1); - name = (char *)p->data + ptr + 1; - } else + if (ptr < p->size - 1) + name = (char *)p->data + ptr + 1; + else + name = "<invalid>"; + } else { name = (char *)pkt_put(p, nl + 1); + } type = htons(*(uint16_t *)pkt_put(p, sizeof(type))); clss = htons(*(uint16_t *)pkt_put(p, sizeof(clss))); |