netdev - Re: [PATCH bpf v2] bpf: fix memory leak in lpm_trie map

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Message-ID: <20180214031719.vbq6yvgtv76sgnvg@ast-mbp.dhcp.thefacebook.com>
Date:   Tue, 13 Feb 2018 19:17:21 -0800
From:   Alexei Starovoitov <alexei.starovoitov@...il.com>
To:     Yonghong Song <yhs@...com>
Cc:     ast@...com, daniel@...earbox.net, netdev@...r.kernel.org,
        kernel-team@...com
Subject: 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 <malat@...ian.org>
> Reported-by: Alexei Starovoitov <ast@...nel.org>
> Tested-by: Mathieu Malaterre <malat@...ian.org>
> Signed-off-by: Yonghong Song <yhs@...com>
> ---
>  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.