Messages in this thread | | | Date | Tue, 15 Nov 2022 10:22:32 +0100 | From | Simon Horman <> | Subject | Re: [PATCH] lag_conf: Added pointer check |
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On Tue, Nov 15, 2022 at 11:56:37AM +0300, Denis Arefev wrote: > [You don't often get email from arefev@swemel.ru. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] > > Return value of a function 'kmalloc_array' is dereferenced at lag_conf.c:347 > without checking for null, but it is usually checked for this function. > > Found by Linux Verification Center (linuxtesting.org) with SVACE. > > Signed-off-by: Denis Arefev <arefev@swemel.ru>
Hi Denis,
thanks for highlighting this problem.
> --- > drivers/net/ethernet/netronome/nfp/flower/lag_conf.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/netronome/nfp/flower/lag_conf.c b/drivers/net/ethernet/netronome/nfp/flower/lag_conf.c > index 63907aeb3884..95ba6e92197d 100644 > --- a/drivers/net/ethernet/netronome/nfp/flower/lag_conf.c > +++ b/drivers/net/ethernet/netronome/nfp/flower/lag_conf.c > @@ -276,7 +276,7 @@ static void nfp_fl_lag_do_work(struct work_struct *work) > > mutex_lock(&lag->lock); > list_for_each_entry_safe(entry, storage, &lag->group_list, list) { > - struct net_device *iter_netdev, **acti_netdevs; > + struct net_device *iter_netdev, **acti_netdevs = NULL;
I don't think it's necessary to set acti_netdevs here as it is always set before use by the call to kmalloc_array().
> struct nfp_flower_repr_priv *repr_priv; > int active_count = 0, slaves = 0; > struct nfp_repr *repr; > @@ -308,6 +308,8 @@ static void nfp_fl_lag_do_work(struct work_struct *work) > > acti_netdevs = kmalloc_array(entry->slave_cnt, > sizeof(*acti_netdevs), GFP_KERNEL); > + if (!acti_netdevs) > + break;
The indentation here doesn't look right.
Regarding the problem at hand, yes, I agree that it seems that kmalloc_array() should be checked. But I am concerned that simply break'ing here may lead to a bad state. And I'd like to ask for some time to examine this more closely.
> /* Include sanity check in the loop. It may be that a bond has > * changed between processing the last notification and the > -- > 2.25.1 >
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