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: 8c290e60fa
("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
zero-sugar-mainline-defconfig
parent
5b801dfb7f
commit
1d4e1eab45
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@ -779,15 +779,20 @@ static void htab_elem_free_rcu(struct rcu_head *head)
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htab_elem_free(htab, l);
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}
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static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
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static void htab_put_fd_value(struct bpf_htab *htab, struct htab_elem *l)
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{
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struct bpf_map *map = &htab->map;
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void *ptr;
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if (map->ops->map_fd_put_ptr) {
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void *ptr = fd_htab_map_get_ptr(map, l);
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ptr = fd_htab_map_get_ptr(map, l);
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map->ops->map_fd_put_ptr(ptr);
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}
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}
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static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
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{
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htab_put_fd_value(htab, l);
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if (htab_is_prealloc(htab)) {
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__pcpu_freelist_push(&htab->freelist, &l->fnode);
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@ -839,6 +844,7 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
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*/
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pl_new = this_cpu_ptr(htab->extra_elems);
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l_new = *pl_new;
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htab_put_fd_value(htab, old_elem);
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*pl_new = old_elem;
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} else {
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struct pcpu_freelist_node *l;
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