Messages in this thread | | | From | Cong Wang <> | Date | Tue, 11 Aug 2020 16:02:51 -0700 | Subject | Re: [PATCH] net: Fix potential memory leak in proto_register() |
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On Mon, Aug 10, 2020 at 5:19 AM Miaohe Lin <linmiaohe@huawei.com> wrote: > > If we failed to assign proto idx, we free the twsk_slab_name but forget to > free the twsk_slab. Add a helper function tw_prot_cleanup() to free these > together and also use this helper function in proto_unregister(). > > Fixes: b45ce32135d1 ("sock: fix potential memory leak in proto_register()") > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > --- > net/core/sock.c | 25 +++++++++++++++---------- > 1 file changed, 15 insertions(+), 10 deletions(-) > > diff --git a/net/core/sock.c b/net/core/sock.c > index 49cd5ffe673e..c9083ad44ea1 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -3406,6 +3406,16 @@ static void sock_inuse_add(struct net *net, int val) > } > #endif > > +static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot) > +{ > + if (!twsk_prot) > + return; > + kfree(twsk_prot->twsk_slab_name); > + twsk_prot->twsk_slab_name = NULL; > + kmem_cache_destroy(twsk_prot->twsk_slab);
Hmm, are you sure you can free the kmem cache name before kmem_cache_destroy()? To me, it seems kmem_cache_destroy() frees the name via slab_kmem_cache_release() via kfree_const(). With your patch, we have a double-free on the name?
Or am I missing anything?
Thanks.
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