On Thu, 28 Jun 2012, Matthieu CASTET wrote:
> If we don't read fast enough hidraw device, hidraw_report_event
> will cycle and we will leak list->buffer.
> Also list->buffer are not free on release.
> After this patch, kmemleak report nothing.
>
> Signed-off-by: Matthieu CASTET <matthieu.castet@xxxxxxxxxx>
> ---
> drivers/hid/hidraw.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
> index 36fa77b..3b6f7bf 100644
> --- a/drivers/hid/hidraw.c
> +++ b/drivers/hid/hidraw.c
> @@ -96,6 +96,7 @@ static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count,
> }
>
> kfree(list->buffer[list->tail].value);
> + list->buffer[list->tail].value = NULL;
> list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
> }
> out:
> @@ -300,6 +301,7 @@ static int hidraw_release(struct inode * inode, struct file * file)
> struct hidraw *dev;
> struct hidraw_list *list = file->private_data;
> int ret;
> + int i;
>
> mutex_lock(&minors_lock);
> if (!hidraw_table[minor]) {
> @@ -317,6 +319,9 @@ static int hidraw_release(struct inode * inode, struct file * file)
> kfree(list->hidraw);
> }
> }
> +
> + for (i = 0; i < HIDRAW_BUFFER_SIZE; ++i)
> + kfree(list->buffer[i].value);
> kfree(list);
> ret = 0;
> unlock:
> @@ -446,12 +451,17 @@ int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
> int ret = 0;
>
> list_for_each_entry(list, &dev->list, node) {
> + int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
> +
> + if (new_head == list->tail)
> + continue;
> +
> if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
> ret = -ENOMEM;
> break;
> }
> list->buffer[list->head].len = len;
> - list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
> + list->head = new_head;
> kill_fasync(&list->fasync, SIGIO, POLL_IN);
> }
>
Applied, thank you Matthieu.
--
Jiri Kosina
SUSE Labs
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