[PATCH 5.16 0110/1039] libbpf: Free up resources used by inner map definition

[Greg Kroah-Hartman]

From: Andrii Nakryiko <andrii@xxxxxxxxxx>

[ Upstream commit 8f7b239ea8cfdc8e64c875ee417fed41431a1f37 ]

It's not enough to just free(map->inner_map), as inner_map itself can
have extra memory allocated, like map name.

Fixes: 646f02ffdd49 ("libbpf: Add BTF-defined map-in-map support")
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Reviewed-by: Hengqi Chen <hengqi.chen@xxxxxxxxx>
Link: https://lore.kernel.org/bpf/20211107165521.9240-3-andrii@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 tools/lib/bpf/libbpf.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 5367bc8e52073..509f3719409bb 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9028,7 +9028,10 @@ int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd)
 		pr_warn("error: inner_map_fd already specified\n");
 		return libbpf_err(-EINVAL);
 	}
-	zfree(&map->inner_map);
+	if (map->inner_map) {
+		bpf_map__destroy(map->inner_map);
+		zfree(&map->inner_map);
+	}
 	map->inner_map_fd = fd;
 	return 0;
 }
-- 
2.34.1