From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Rogers Subject: [RFC PATCH v3 04/14] libbpf: Fix memory leak and possible double-free in hashmap__clear Date: Thu, 7 May 2020 22:36:19 -0700 Message-ID: <20200508053629.210324-5-irogers@google.com> References: <20200508053629.210324-1-irogers@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <20200508053629.210324-1-irogers@google.com> Sender: netdev-owner@vger.kernel.org To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , John Fastabend , KP Singh , Kajol Jain , Andi Kleen , John Garry , Jin Yao , Kan Liang , Cong Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, Vince Weaver , Stephane Eranian , Alston Tang , Ian Rogers List-Id: linux-perf-users.vger.kernel.org From: Andrii Nakryiko Fix memory leak in hashmap_clear() not freeing hashmap_entry structs for each of the remaining entries. Also NULL-out bucket list to prevent possible double-free between hashmap__clear() and hashmap__free(). Running test_progs-asan flavor clearly showed this problem. Reported-by: Alston Tang Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200429012111.277390-5-andriin@fb.com Signed-off-by: Ian Rogers --- tools/lib/bpf/hashmap.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/tools/lib/bpf/hashmap.c b/tools/lib/bpf/hashmap.c index 54c30c802070..cffb96202e0d 100644 --- a/tools/lib/bpf/hashmap.c +++ b/tools/lib/bpf/hashmap.c @@ -59,7 +59,14 @@ struct hashmap *hashmap__new(hashmap_hash_fn hash_fn, void hashmap__clear(struct hashmap *map) { + struct hashmap_entry *cur, *tmp; + int bkt; + + hashmap__for_each_entry_safe(map, cur, tmp, bkt) { + free(cur); + } free(map->buckets); + map->buckets = NULL; map->cap = map->cap_bits = map->sz = 0; } -- 2.26.2.645.ge9eca65c58-goog