(Added linux-wireless, since this is a wireless driver) On Sunday, April 9, 2017 10:23:20 PM CEST Myungho Jung wrote: > Kernel panic is caused by trying to dereference null pointer. Check if > the pointer is null before freeing space. Do you have the kernel panic somewhere? I think you have an even bigger problem: You see, in order to get EEPROM readback and rx_stats feedback you need to sent a request to the firmware and if the response's req_id cookies don't match, you end up filling up the very limited device address space. As for adding if (!skb) checks. I think kfree, kfree_skb, dev_kfree_skb (aka consume_skb) all check for null pointers already. So the logical thing to do would be to make dev_kfree_skb_irq (which would also fix dev_kfree_skb_any) consistent with kfree, kfree_skb, dev_kfree_skb and add the check there. > Signed-off-by: Myungho Jung <mhjungk@xxxxxxxxx> > --- > drivers/net/wireless/intersil/p54/txrx.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wireless/intersil/p54/txrx.c b/drivers/net/wireless/intersil/p54/txrx.c > index 1af7da0..8956061 100644 > --- a/drivers/net/wireless/intersil/p54/txrx.c > +++ b/drivers/net/wireless/intersil/p54/txrx.c > @@ -503,7 +503,9 @@ static void p54_rx_eeprom_readback(struct p54_common *priv, > > priv->eeprom = NULL; > tmp = p54_find_and_unlink_skb(priv, hdr->req_id); > - dev_kfree_skb_any(tmp); > + if (unlikely(!tmp)) > + dev_kfree_skb_any(tmp); > + > complete(&priv->eeprom_comp); > } > > @@ -597,7 +599,9 @@ static void p54_rx_stats(struct p54_common *priv, struct sk_buff *skb) > } > > tmp = p54_find_and_unlink_skb(priv, hdr->req_id); > - dev_kfree_skb_any(tmp); > + if (unlikely(!tmp)) > + dev_kfree_skb_any(tmp); > + > complete(&priv->stat_comp); > } > >
