Re: [PATCH] Fix two potential mem leaks in MPT Fusion (mpt_attach())

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 2 Aug 2007 01:55:33 +0200
Jesper Juhl <jesper.juhl@gmail.com> wrote:

> Greetings & Salutations,
> 
> The Coverity checker spotted two potential memory leaks in 
> drivers/message/fusion/mptbase.c::mpt_attach().
> 
> There are two returns that may leak the storage allocated for 
> 'ioc' (sizeof(MPT_ADAPTER) bytes).
> A simple fix would be to simply add two kfree() calls before 
> the return statements, but a better fix (that this patch 
> implements) is to reorder the code so that if we hit the first 
> return condition we don't have to do the allocation at all and 
> then just add a kfree() call for the second case.
> 
> Please consider applying.  Patch has been compile tested only.
> 
> 

umm,

> ---
> 
>  drivers/message/fusion/mptbase.c |   13 +++++++------
>  1 files changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/message/fusion/mptbase.c b/drivers/message/fusion/mptbase.c
> index e866dac..f9bb705 100644
> --- a/drivers/message/fusion/mptbase.c
> +++ b/drivers/message/fusion/mptbase.c
> @@ -1393,18 +1393,18 @@ mpt_attach(struct pci_dev *pdev, const struct pci_device_id *id)
>  	struct proc_dir_entry *dent, *ent;
>  #endif
>  
> +	if (mpt_debug_level)
> +		printk(KERN_INFO MYNAM ": mpt_debug_level=%xh\n", mpt_debug_level);
> +
> +	if (pci_enable_device(pdev))
> +		return r;
> +
>  	ioc = kzalloc(sizeof(MPT_ADAPTER), GFP_ATOMIC);

Why on earth is that using GFP_ATOMIC?  This function later goes on to
create procfs files and such things.




y'know, we could have a debug option which will spit warnings if someone
does a !__GFP_WAIT allocation while !in_atomic() (only works if
CONFIG_PREEMPT).  

But please, make it depend on !CONFIG_AKPM.  I shudder to think about all
the stuff it would pick up.