- bumble/sdp.py: replace raise ValueError with raise InvalidPacketError
in DataElement.list_from_bytes depth guard. InvalidPacketError
already imported at line 34 and extends ValueError so the existing
regression test continues to match.
- tests/sdp_test.py: remove duplicate 'import pytest' inside
test_nested_sequence_recursion_guard; pytest already imported at
module top (line 23).
Threading.local counter left as-is per zxzxwu's 'leave it here and
refactor later' comment on the PR.
DataElement.from_bytes -> list_from_bytes -> (SEQUENCE/ALTERNATIVE
constructor dispatches back to list_from_bytes) had no depth limit. A
malicious SDP peer could send a PDU of a few kilobytes containing ~1000
nested SEQUENCE tags and exhaust the Python recursion stack, crashing the
host with an unhandled RecursionError propagating out of the SDP handler.
Reachable via: any remote Bluetooth device that Bumble performs SDP
service discovery against (default during Classic connection setup).
Same family as PR #912 (ATT_PDU.from_bytes empty PDU IndexError) - remote
unchecked-input parser crash in the Bluetooth stack.
Fix: thread-local depth counter, cap nesting at 32 (well above anything a
legitimate service record uses). Added two regression tests covering the
deep-nesting reject path and normal 16-level-nested SEQUENCE parsing.
Reproducer (4.5 KB payload, deterministic crash on 0.0.228):
from bumble.sdp import DataElement
inner = b"\x35\x00"
for _ in range(1500):
size = len(inner)
if size < 65535:
inner = bytes([0x36, (size >> 8) & 0xFF, size & 0xFF]) + inner
DataElement.from_bytes(inner) # RecursionError before fix
Signed-off-by: ibondarenko1 <ibondarenko1@users.noreply.github.com>
