From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Simon Wunderlich Date: Tue, 11 Feb 2014 18:35:52 +0100 References: <1391874306-15627-1-git-send-email-sw@simonwunderlich.de> <52FA5D35.6020809@meshcoding.com> In-Reply-To: <52FA5D35.6020809@meshcoding.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <201402111835.52663.sw@simonwunderlich.de> Subject: Re: [B.A.T.M.A.N.] [PATCH-maint] batman-adv: fix potential orig_node reference leak Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Antonio Quartulli Cc: b.a.t.m.a.n@lists.open-mesh.org > On 08/02/14 16:45, Simon Wunderlich wrote: > > Since batadv_orig_node_new() sets the refcount to two, assuming that > > the calling function will use a reference for putting the orig_node into > > a hash or similar, both references must be freed if initialization of > > the orig_node fails. Otherwise that object may be leaked in that error > > case. > > > > Reported-by: Antonio Quartulli > > Signed-off-by: Simon Wunderlich > > --- > > > > bat_iv_ogm.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/bat_iv_ogm.c b/bat_iv_ogm.c > > index 6f4fcdc..6000337 100644 > > --- a/bat_iv_ogm.c > > +++ b/bat_iv_ogm.c > > @@ -256,6 +256,8 @@ batadv_iv_ogm_orig_get(struct batadv_priv *bat_priv, > > const uint8_t *addr) > > > > free_bcast_own: > > kfree(orig_node->bat_iv.bcast_own); > > > > free_orig_node: > > + /* free twice, as batadv_orig_node_new set refcount to 2 */ > > + batadv_orig_node_free_ref(orig_node); > > > > batadv_orig_node_free_ref(orig_node); > > Coudln't we just invoke kfree(orig_node) here ? I think that if we hit > this point it is because the node has not added to the hash and > therefore it i snot used in any other context. This way we avoid the > double free_ref() and we don't trgger the whole RCU mechanism. > > Or am I missing something? What about already allocated substructures like bat_iv.bcast_own, bat_iv.bacst_own_sum etc? Of course we could find out which is already allocated and free that too, but that orig node free function does already that. Cheers, Simon