Re: [PATCH] hv: use correct order when freeing monitor_pages

From: Jason Wang
Date: Tue May 27 2014 - 23:23:14 EST


On 05/28/2014 01:16 AM, Radim KrÄmÃÅ wrote:
> We try to free two pages when only one has been allocated.
> Cleanup path is unlikely, so I haven't found any trace that would fit,
> but I hope that free_pages_prepare() does catch it.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
> ---
> Cc'd stable because the worst-case looks hard to debug.
> Btw. the module can't get unloaded after we successfully connect?
>
> drivers/hv/connection.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> index 7f10c15..e84f452 100644
> --- a/drivers/hv/connection.c
> +++ b/drivers/hv/connection.c
> @@ -224,8 +224,8 @@ cleanup:
> vmbus_connection.int_page = NULL;
> }
>
> - free_pages((unsigned long)vmbus_connection.monitor_pages[0], 1);
> - free_pages((unsigned long)vmbus_connection.monitor_pages[1], 1);
> + free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0);
> + free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0);
> vmbus_connection.monitor_pages[0] = NULL;
> vmbus_connection.monitor_pages[1] = NULL;
>

Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
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