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bpf: Call the missed btf_record_free() when map creation fails

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When security_bpf_map_create() in map_create() fails, map_create() will
call btf_put() and ->map_free() callback to free the map. It doesn't
free the btf_record of map value, so add the missed btf_record_free()
when map creation fails.

However btf_record_free() needs to be called after ->map_free() just
like bpf_map_free_deferred() did, because ->map_free() may use the
btf_record to free the special fields in preallocated map value. So
factor out bpf_map_free() helper to free the map, btf_record, and btf
orderly and use the helper in both map_create() and
bpf_map_free_deferred().

Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240912012845.3458483-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Hou Tao
2024-09-12 09:28:44 +08:00
committed by Alexei Starovoitov
parent 211bf9cf17
commit 87e9675a0d
1 changed files with 12 additions and 7 deletions
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kernel/bpf/syscall.c
+12 -7
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@@ -735,15 +735,11 @@ void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
}
}
/* called from workqueue */
static void bpf_map_free_deferred(struct work_struct *work)
static void bpf_map_free(struct bpf_map *map)
{
struct bpf_map *map = container_of(work, struct bpf_map, work);
struct btf_record *rec = map->record;
struct btf *btf = map->btf;
security_bpf_map_free(map);
bpf_map_release_memcg(map);
/* implementation dependent freeing */
map->ops->map_free(map);
/* Delay freeing of btf_record for maps, as map_free
@@ -762,6 +758,16 @@ static void bpf_map_free_deferred(struct work_struct *work)
btf_put(btf);
}
/* called from workqueue */
static void bpf_map_free_deferred(struct work_struct *work)
{
struct bpf_map *map = container_of(work, struct bpf_map, work);
security_bpf_map_free(map);
bpf_map_release_memcg(map);
bpf_map_free(map);
}
static void bpf_map_put_uref(struct bpf_map *map)
{
if (atomic64_dec_and_test(&map->usercnt)) {
@@ -1413,8 +1419,7 @@ static int map_create(union bpf_attr *attr)
free_map_sec:
security_bpf_map_free(map);
free_map:
btf_put(map->btf);
map->ops->map_free(map);
bpf_map_free(map);
put_token:
bpf_token_put(token);
return err;