[PATCH] iwlagn: fix rmmod crash

[PATCH] iwlagn: fix rmmod crash

[Stanislaw Gruszka]

priv->bus.bus_specific pointer is used after priv structures was freed,
in iwl_pci_remove(), what make ugly rmmod crash. This bug was introduced
by current pci changes.

On the way remove fake check, if prober error code is returned from
.probe() function, .remove() will never be called be null drvdata.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
 drivers/net/wireless/iwlwifi/iwl-pci.c |    7 ++-----
 1 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/iwl-pci.c b/drivers/net/wireless/iwlwifi/iwl-pci.c
index 7328fbf..55a04b8 100644
--- a/drivers/net/wireless/iwlwifi/iwl-pci.c
+++ b/drivers/net/wireless/iwlwifi/iwl-pci.c
@@ -496,14 +496,11 @@ static void iwl_pci_down(void *bus)
 static void __devexit iwl_pci_remove(struct pci_dev *pdev)
 {
 	struct iwl_priv *priv = pci_get_drvdata(pdev);
-
-	/* This can happen if probe failed */
-	if (unlikely(!priv))
-		return;
+	void *bus_specific = priv->bus.bus_specific;
 
 	iwl_remove(priv);
 
-	iwl_pci_down(IWL_BUS_GET_PCI_BUS(&priv->bus));
+	iwl_pci_down(bus_specific);
 }
 
 #ifdef CONFIG_PM
-- 
1.7.1

Re: [PATCH] iwlagn: fix rmmod crash

[Emmanuel Grumbach]

On Fri, Jun 24, 2011 at 12:34, Stanislaw Gruszka <sgruszka@redhat.com> wrote:
> priv->bus.bus_specific pointer is used after priv structures was freed,
> in iwl_pci_remove(), what make ugly rmmod crash. This bug was introduced
> by current pci changes.

Oops... You are definitely right. Strangely enough, I was very lucky
when I run the 500 cycles of rmmod insmod.

Thanks for the fix !

Re: [PATCH] iwlagn: fix rmmod crash

[wwguy]

On Fri, 2011-06-24 at 02:34 -0700, Stanislaw Gruszka wrote:
> priv->bus.bus_specific pointer is used after priv structures was freed,
> in iwl_pci_remove(), what make ugly rmmod crash. This bug was introduced
> by current pci changes.
> 
> On the way remove fake check, if prober error code is returned from
> .probe() function, .remove() will never be called be null drvdata.
> 
> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
> ---
you are right, thank you very much for catch this.

Wey