From 229bf8bf4d910510bc1a2fd0b89bd467cd71050d Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Tue, 28 Apr 2020 18:21:04 -0700 Subject: [PATCH] libbpf: Fix memory leak and possible double-free in hashmap__clear 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 --- 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 54c30c8..cffb962 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; } -- 2.7.4