Commit 229bf8bf authored Apr 28, 2020 by Andrii Nakryiko Committed by Alexei Starovoitov Apr 28, 2020

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 <alston64@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429012111.277390-5-andriin@fb.com

parent 42fce2cf

tools/lib/bpf/hashmap.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

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