Re: [PATCH] net: missing lock releases in ipmr_base.c

From: Stephen Hemminger
Date: Fri Jan 21 2022 - 11:13:22 EST


On Fri, 21 Jan 2022 11:22:10 +0800
ycaibb <ycaibb@xxxxxxxxx> wrote:

> From: Ryan Cai <ycaibb@xxxxxxxxx>
>
> In method mr_mfc_seq_idx, the lock it->lock and rcu_read_lock are not released when pos-- == 0 is true.
>
> Signed-off-by: Ryan Cai <ycaibb@xxxxxxxxx>
> ---
> net/ipv4/ipmr_base.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/net/ipv4/ipmr_base.c b/net/ipv4/ipmr_base.c
> index aa8738a91210..c4a247024c85 100644
> --- a/net/ipv4/ipmr_base.c
> +++ b/net/ipv4/ipmr_base.c
> @@ -154,6 +154,7 @@ void *mr_mfc_seq_idx(struct net *net,
> it->cache = &mrt->mfc_cache_list;
> list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
> if (pos-- == 0)
> + rcu_read_unlock();
> return mfc;
> rcu_read_unlock();
>
> @@ -161,6 +162,7 @@ void *mr_mfc_seq_idx(struct net *net,
> it->cache = &mrt->mfc_unres_queue;
> list_for_each_entry(mfc, it->cache, list)
> if (pos-- == 0)
> + spin_unlock_bh(it->lock);
> return mfc;
> spin_unlock_bh(it->lock);
>

Another buggy patch, perhaps you write python or research papers?