[lkml]   [2007]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH][RESEND] Avoid possible NULL pointer deref in 3c359 driver
(Resending old patch originally submitted at 1/7-2007 02:19)

In xl_freemem(), if dev_if is NULL, the line
struct xl_private *xl_priv =(struct xl_private *)dev->priv;
will cause a NULL pointer dereference. However, if we move
that assignment below the 'if' statement that tests for a NULL
'dev', then that NULL deref can never happen.
It never hurts to be safe :-)

Signed-off-by: Jesper Juhl <>

diff --git a/drivers/net/tokenring/3c359.c b/drivers/net/tokenring/3c359.c
index e22a3f5..671f4da 100644
--- a/drivers/net/tokenring/3c359.c
+++ b/drivers/net/tokenring/3c359.c
@@ -1044,15 +1044,17 @@ static void xl_freemem(struct net_device *dev)
static irqreturn_t xl_interrupt(int irq, void *dev_id)
struct net_device *dev = (struct net_device *)dev_id;
- struct xl_private *xl_priv =(struct xl_private *)dev->priv;
- u8 __iomem * xl_mmio = xl_priv->xl_mmio ;
- u16 intstatus, macstatus ;
+ struct xl_private *xl_priv;
+ u8 __iomem * xl_mmio;
+ u16 intstatus, macstatus;

if (!dev) {
- printk(KERN_WARNING "Device structure dead, aaahhhh !\n") ;
+ printk(KERN_WARNING "3c359: Device structure dead, aaahhhh!\n");
return IRQ_NONE;

+ xl_priv = (struct xl_private *)dev->priv;
+ xl_mmio = xl_priv->xl_mmio;
intstatus = readw(xl_mmio + MMIO_INTSTATUS) ;

if (!(intstatus & 1)) /* We didn't generate the interrupt */

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-08-04 20:37    [W:0.022 / U:8.200 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site