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