python-dns/SOURCES/CVE-2023-29483.patch

100 lines
3.5 KiB
Diff

From a77e0c662c6d5b8224ac1e283aee8353bcd1536e Mon Sep 17 00:00:00 2001
From: Lumir Balhar <lbalhar@redhat.com>
Date: Mon, 22 Apr 2024 16:49:15 +0200
Subject: [PATCH] CVE-2023-29483
---
dns/query.py | 60 +++++++++++++++++++++++++++++++++++-----------------
1 file changed, 41 insertions(+), 19 deletions(-)
diff --git a/dns/query.py b/dns/query.py
index 19b9fbb..2dba3cc 100644
--- a/dns/query.py
+++ b/dns/query.py
@@ -170,6 +170,22 @@ def _addresses_equal(af, a1, a2):
return n1 == n2 and a1[1:] == a2[1:]
+def _matches_destination(af, from_address, destination, ignore_unexpected):
+ # Check that from_address is appropriate for a response to a query
+ # sent to destination.
+ if not destination:
+ return True
+ if _addresses_equal(af, from_address, destination) or (
+ dns.inet.is_multicast(destination[0]) and from_address[1:] == destination[1:]
+ ):
+ return True
+ elif ignore_unexpected:
+ return False
+ raise UnexpectedSource(
+ f"got a response from {from_address} instead of " f"{destination}"
+ )
+
+
def _destination_and_source(af, where, port, source, source_port):
# Apply defaults and compute destination and source tuples
# suitable for use in connect(), sendto(), or bind().
@@ -194,7 +210,7 @@ def _destination_and_source(af, where, port, source, source_port):
def udp(q, where, timeout=None, port=53, af=None, source=None, source_port=0,
- ignore_unexpected=False, one_rr_per_rrset=False):
+ ignore_unexpected=False, one_rr_per_rrset=False, ignore_errors=False):
"""Return the response obtained after sending a query via UDP.
@param q: the query
@@ -239,26 +255,32 @@ def udp(q, where, timeout=None, port=53, af=None, source=None, source_port=0,
while 1:
_wait_for_readable(s, expiration)
(wire, from_address) = s.recvfrom(65535)
- if _addresses_equal(af, from_address, destination) or \
- (dns.inet.is_multicast(where) and
- from_address[1:] == destination[1:]):
- break
- if not ignore_unexpected:
- raise UnexpectedSource('got a response from '
- '%s instead of %s' % (from_address,
- destination))
- finally:
- if begin_time is None:
- response_time = 0
- else:
+ if not _matches_destination(
+ s.family, from_address, destination, ignore_unexpected
+ ):
+ continue
+
response_time = time.time() - begin_time
+
+ try:
+ r = dns.message.from_wire(wire, keyring=q.keyring, request_mac=q.mac,
+ one_rr_per_rrset=one_rr_per_rrset)
+ r.time = response_time
+ except Exception:
+ if ignore_errors:
+ continue
+ else:
+ raise
+
+ if q.is_response(r):
+ return r
+ else:
+ if ignore_errors:
+ continue
+ else:
+ raise BadResponse
+ finally:
s.close()
- r = dns.message.from_wire(wire, keyring=q.keyring, request_mac=q.mac,
- one_rr_per_rrset=one_rr_per_rrset)
- r.time = response_time
- if not q.is_response(r):
- raise BadResponse
- return r
def _net_read(sock, count, expiration):
--
2.44.0