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authorAndrii Nakryiko <andriin@fb.com>2020-07-28 21:09:12 -0700
committerDaniel Borkmann <daniel@iogearbox.net>2020-07-30 01:30:22 +0200
commit1d4e1eab456e1ee92a94987499b211db05f900ea (patch)
tree5b82ae2c43008bf5b78126fad7b2762c1d1514b8
parent5b801dfb7feb2738975d80223efc2fc193e55573 (diff)
bpf: Fix map leak in HASH_OF_MAPS map
Fix HASH_OF_MAPS bug of not putting inner map pointer on bpf_map_elem_update() operation. This is due to per-cpu extra_elems optimization, which bypassed free_htab_elem() logic doing proper clean ups. Make sure that inner map is put properly in optimized case as well. Fixes: 8c290e60fa2a ("bpf: fix hashmap extra_elems logic") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200729040913.2815687-1-andriin@fb.com
-rw-r--r--kernel/bpf/hashtab.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index b4b288a3c3c9..b32cc8ce8ff6 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -779,15 +779,20 @@ static void htab_elem_free_rcu(struct rcu_head *head)
htab_elem_free(htab, l);
}
-static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
+static void htab_put_fd_value(struct bpf_htab *htab, struct htab_elem *l)
{
struct bpf_map *map = &htab->map;
+ void *ptr;
if (map->ops->map_fd_put_ptr) {
- void *ptr = fd_htab_map_get_ptr(map, l);
-
+ ptr = fd_htab_map_get_ptr(map, l);
map->ops->map_fd_put_ptr(ptr);
}
+}
+
+static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
+{
+ htab_put_fd_value(htab, l);
if (htab_is_prealloc(htab)) {
__pcpu_freelist_push(&htab->freelist, &l->fnode);
@@ -839,6 +844,7 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
*/
pl_new = this_cpu_ptr(htab->extra_elems);
l_new = *pl_new;
+ htab_put_fd_value(htab, old_elem);
*pl_new = old_elem;
} else {
struct pcpu_freelist_node *l;