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| author | Alexey Kodanev <aleksei.kodanev@bell-sw.com> | 2023-03-22 17:48:40 +0300 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2023-04-07 20:44:20 -0400 |
| commit | 77327ed064bd57b0e1865cd0e0364057ff4a53b4 (patch) | |
| tree | 456aa3bfdc5ff2c84c5e1eb68bf49002d386adf3 | |
| parent | 1d5750b95c06913a1f18a995481276d698d20fae (diff) | |
| download | musl-77327ed064bd57b0e1865cd0e0364057ff4a53b4.tar.gz | |
dns: check length field in tcp response message
The received length field in the message may be greater than the
size of the 'answer' buffer in which the message resides. Currently,
ABUF_SIZE is 768. And if we get a larger 'alens[i]', it will result
in an out-of-bounds reading in __dns_parse().
To fix this, limit the length to the size of the received buffer.
| -rw-r--r-- | src/network/lookup_name.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/src/network/lookup_name.c b/src/network/lookup_name.c index f268bcda..4281482e 100644 --- a/src/network/lookup_name.c +++ b/src/network/lookup_name.c @@ -179,6 +179,7 @@ static int name_from_dns(struct address buf[static MAXADDRS], char canon[static for (i=nq-1; i>=0; i--) { ctx.rrtype = qtypes[i]; + if (alens[i] > sizeof(abuf[i])) alens[i] = sizeof abuf[i]; __dns_parse(abuf[i], alens[i], dns_parse_callback, &ctx); } |