Re: [PATCH] ibmasm driver: don't use previously freed pointer

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, 2006-02-03 at 22:02, Greg KH wrote:
> On Fri, Feb 03, 2006 at 02:26:38PM -0800, Max Asbock wrote:
> > ibmasm driver:
> > Fix the command_put() function which uses a pointer for a spinlock that
> > can be freed before dereferencing it.
> > 
> > Signed-off-by: Max Asbock [email protected]
> > 
> > ---
> > 
> > diff -burpN linux-2.6.16-rc1/drivers/misc/ibmasm/ibmasm.h linux-2.6.16-rc1.ibmasm/drivers/misc/ibmasm/ibmasm.h
> > --- linux-2.6.16-rc1/drivers/misc/ibmasm/ibmasm.h	2006-02-01 11:50:01.000000000 -0800
> > +++ linux-2.6.16-rc1.ibmasm/drivers/misc/ibmasm/ibmasm.h	2006-02-03 13:57:42.000000000 -0800
> > @@ -101,10 +101,11 @@ struct command {
> >  static inline void command_put(struct command *cmd)
> >  {
> >  	unsigned long flags;
> > +	spinlock_t *lock = cmd->lock;
> >  
> > -	spin_lock_irqsave(cmd->lock, flags);
> > +	spin_lock_irqsave(lock, flags);
> >          kobject_put(&cmd->kobj);
> > -	spin_unlock_irqrestore(cmd->lock, flags);
> > +	spin_unlock_irqrestore(lock, flags);
> >  }
> 
> If this patch is true, doesn't the spinlock the pointer is pointing out
> still get deleted?
> 
> Yes you save a pointer off, but it looks like the problem is still
> present.
> 
> Or am I missing something?
> 

The lock pointer in struct command points to a spinlock outside the
structure that doesn't get deleted.

max

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux