diff options
| author | Yonghong Song <yhs@fb.com> | 2018-03-08 13:16:43 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-11 16:25:13 +0100 |
| commit | f154de29a46b7498f957c7b22528571eb8e11211 (patch) | |
| tree | ecb81f98e406162226ba028085bcb64a518d1a0b | |
| parent | da43a222a7593b1336d680f15fe2867b7bf6a085 (diff) | |
bpf: fix memory leak in lpm_trie map_free callback function
[ upstream commit 9a3efb6b661f71d5675369ace9257833f0e78ef3 ]
There is a memory leak happening in lpm_trie map_free callback
function trie_free. The trie structure itself does not get freed.
Also, trie_free function did not do synchronize_rcu before freeing
various data structures. This is incorrect as some rcu_read_lock
region(s) for lookup, update, delete or get_next_key may not complete yet.
The fix is to add synchronize_rcu in the beginning of trie_free.
The useless spin_lock is removed from this function as well.
Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation")
Reported-by: Mathieu Malaterre <malat@debian.org>
Reported-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/bpf/lpm_trie.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index 885e45479680..61c0b530c443 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -560,7 +560,10 @@ static void trie_free(struct bpf_map *map) struct lpm_trie_node __rcu **slot; struct lpm_trie_node *node; - raw_spin_lock(&trie->lock); + /* Wait for outstanding programs to complete + * update/lookup/delete/get_next_key and free the trie. + */ + synchronize_rcu(); /* Always start at the root and walk down to a node that has no * children. Then free that node, nullify its reference in the parent @@ -574,7 +577,7 @@ static void trie_free(struct bpf_map *map) node = rcu_dereference_protected(*slot, lockdep_is_held(&trie->lock)); if (!node) - goto unlock; + goto out; if (rcu_access_pointer(node->child[0])) { slot = &node->child[0]; @@ -592,8 +595,8 @@ static void trie_free(struct bpf_map *map) } } -unlock: - raw_spin_unlock(&trie->lock); +out: + kfree(trie); } static int trie_get_next_key(struct bpf_map *map, void *key, void *next_key) |