From: Hangbin Liu liuhangbin@gmail.com
[ Upstream commit a0f2b7acb4b1d29127ff99c714233b973afd1411 ]
Previously we forgot to close the map fd if bpf_map_update_elem() failed during map slot init, which will leak map fd.
Let's move map slot initialization to new function init_map_slots() to simplify the code. And close the map fd if init slot failed.
Reported-by: Andrii Nakryiko andrii.nakryiko@gmail.com Signed-off-by: Hangbin Liu liuhangbin@gmail.com Signed-off-by: Alexei Starovoitov ast@kernel.org Acked-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20201006021345.3817033-2-liuhangbin@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/bpf/libbpf.c | 55 ++++++++++++++++++++++++++---------------- 1 file changed, 34 insertions(+), 21 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 8b71a31ca4a97..edd6f7b7d9b82 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3841,6 +3841,36 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map) return 0; }
+static int init_map_slots(struct bpf_map *map) +{ + const struct bpf_map *targ_map; + unsigned int i; + int fd, err; + + for (i = 0; i < map->init_slots_sz; i++) { + if (!map->init_slots[i]) + continue; + + targ_map = map->init_slots[i]; + fd = bpf_map__fd(targ_map); + err = bpf_map_update_elem(map->fd, &i, &fd, 0); + if (err) { + err = -errno; + pr_warn("map '%s': failed to initialize slot [%d] to map '%s' fd=%d: %d\n", + map->name, i, targ_map->name, + fd, err); + return err; + } + pr_debug("map '%s': slot [%d] set to map '%s' fd=%d\n", + map->name, i, targ_map->name, fd); + } + + zfree(&map->init_slots); + map->init_slots_sz = 0; + + return 0; +} + static int bpf_object__create_maps(struct bpf_object *obj) { @@ -3883,28 +3913,11 @@ bpf_object__create_maps(struct bpf_object *obj) }
if (map->init_slots_sz) { - for (j = 0; j < map->init_slots_sz; j++) { - const struct bpf_map *targ_map; - int fd; - - if (!map->init_slots[j]) - continue; - - targ_map = map->init_slots[j]; - fd = bpf_map__fd(targ_map); - err = bpf_map_update_elem(map->fd, &j, &fd, 0); - if (err) { - err = -errno; - pr_warn("map '%s': failed to initialize slot [%d] to map '%s' fd=%d: %d\n", - map->name, j, targ_map->name, - fd, err); - goto err_out; - } - pr_debug("map '%s': slot [%d] set to map '%s' fd=%d\n", - map->name, j, targ_map->name, fd); + err = init_map_slots(map); + if (err < 0) { + zclose(map->fd); + goto err_out; } - zfree(&map->init_slots); - map->init_slots_sz = 0; }
if (map->pin_path && !map->pinned) {