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

From: Andrew Morton
Date: Wed Aug 01 2007 - 20:27:23 EST


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


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