Memory leak in _dbm.open (libdb) when file creation fails (ENOENT) #144069
Description
Bug report
Bug description:
import _dbm
import os
# Ensure we are pointing to a directory that definitely does not exist
# to trigger the specific 'ENOENT' failure path in the underlying library.
filename = "non_existent_directory_xyz/test.db"
# The leak occurs here:
# 1. _dbm.open calls into libdb (Berkeley DB via ndbm interface).
# 2. libdb allocates internal structures.
# 3. libdb attempts to open/create the file and fails because the directory is missing.
# 4. The error propagates up, but the internal structures are not fully freed.
try:
_dbm.open(filename, 'c', 0o666)
except OSError:
pass=================================================================
==206240==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 1456 byte(s) in 1 object(s) allocated from:
#0 0x57cae5ceefb4 in malloc (/home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/python+0x385fb4) (BuildId: 066bbf729257aedd916af3db6dae04834cf3a8ba)
#1 0x6d3a96c8e454 in __os_malloc (/lib/x86_64-linux-gnu/libdb-5.3.so+0x146454) (BuildId: 6dc2ccece58bc114d1ce20f521a527cc5862e054)
Indirect leak of 3814 byte(s) in 10 object(s) allocated from:
#0 0x57cae5ceefb4 in malloc (/home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/python+0x385fb4) (BuildId: 066bbf729257aedd916af3db6dae04834cf3a8ba)
#1 0x6d3a96c8e454 in __os_malloc (/lib/x86_64-linux-gnu/libdb-5.3.so+0x146454) (BuildId: 6dc2ccece58bc114d1ce20f521a527cc5862e054)
SUMMARY: AddressSanitizer: 5270 byte(s) leaked in 11 allocation(s).
Is it likely an upstream bug from libdb?
CPython versions tested on:
CPython main branch
Operating systems tested on:
Linux