Re: [PATCH bpf v2] bpf: fix memory leak in lpm_trie map_free callback function

On Tue, Feb 13, 2018 at 07:00:21PM -0800, Yonghong Song wrote:

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 <redacted>
Reported-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Mathieu Malaterre <redacted>
Signed-off-by: Yonghong Song <redacted>
---
 kernel/bpf/lpm_trie.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

v1->v2:
  Make comments more precise and make label name more appropriate,
  as suggested by Daniel

Applied to bpf tree, Thanks Yonghong.