On Tue, Dec 21, 2010 at 7:05 AM, Jesper Juhl <jj@xxxxxxxxxxxxx> wrote:
> On Mon, 20 Dec 2010, Minchan Kim wrote:
>
>> On Mon, Dec 20, 2010 at 7:10 AM, Jesper Juhl <jj@xxxxxxxxxxxxx> wrote:
>> > Hi,
>> >
>> > The NODEMASK_ALLOC macro dynamically allocates memory for its second
>> > argument ('nodes_allowed' in this context).
>> > In nr_hugepages_store_common() we may abort early if strict_strtoul()
>> > fails, but in that case we do not free the memory already allocated to
>> > 'nodes_allowed', causing a memory leak.
>> > This patch closes the leak by freeing the memory in the error path.
>> >
>> >
>> > Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
>> > ---
>> > hugetlb.c | 4 +++-
>> > 1 file changed, 3 insertions(+), 1 deletion(-)
>> >
>> > compile tested only
>> >
>> > diff --git a/mm/hugetlb.c b/mm/hugetlb.c
>> > index 8585524..9fdcc35 100644
>> > --- a/mm/hugetlb.c
>> > +++ b/mm/hugetlb.c
>> > @@ -1439,8 +1439,10 @@ static ssize_t nr_hugepages_store_common(bool obey_mempolicy,
>> > NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY);
>> >
>> > err = strict_strtoul(buf, 10, &count);
>> > - if (err)
>> > + if (err) {
>> > + kfree(nodes_allowed);
>>
>> Nice catch. But use NODEMASK_FREE. It might be not kmalloced object.
>>
> Right. I just checked the macro and it used kmalloc(), so I just wrote
> kfree. But you are right, NODEMASK_FREE is the right thing to use here.
> Updated patch below.
>
>
> Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx>
Could you resend the completed patch to save Andrew trouble?
--
Kind regards,
Minchan Kim
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/
Don't email: <a href