Re: [PATCH] tipc: check for null after calling kmemdup

[Jakub Kicinski]

On Thu, 11 Nov 2021 19:06:18 -0500 Jon Maloy wrote:
> On 11/11/21 15:59, Tadeusz Struk wrote:
> > kmemdup can return a null pointer so need to check for it, otherwise
> > the null key will be dereferenced later in tipc_crypto_key_xmit as
> > can be seen in the trace [1].

> > [1] https://syzkaller.appspot.com/bug?id=bca180abb29567b189efdbdb34cbf7ba851c2a58
> >
> > Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> > Signed-off-by: Tadeusz Struk <tadeusz.struk@xxxxxxxxxx>
> > ---
> >   net/tipc/crypto.c | 5 +++++
> >   1 file changed, 5 insertions(+)
> >
> > diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c
> > index dc60c32bb70d..988a343f9fd5 100644
> > --- a/net/tipc/crypto.c
> > +++ b/net/tipc/crypto.c
> > @@ -597,6 +597,11 @@ static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey,
> >   	tmp->cloned = NULL;
> >   	tmp->authsize = TIPC_AES_GCM_TAG_SIZE;
> >   	tmp->key = kmemdup(ukey, tipc_aead_key_size(ukey), GFP_KERNEL);
> > +	if (!tmp->key) {
> > +		free_percpu(tmp->tfm_entry);
> > +		kfree_sensitive(tmp);
> > +		return -ENOMEM;
> > +	}

> Acked-by: Jon Maloy <jmaloy@xxxxxxxxxx>

Hm, shouldn't we free all the tfm entries here?