summaryrefslogtreecommitdiff
path: root/drivers/usb/host/isp1760-hcd.c
diff options
context:
space:
mode:
authorArvid Brodin <arvid.brodin@enea.com>2011-11-23 21:13:02 +0400
committerGreg Kroah-Hartman <gregkh@suse.de>2011-11-27 08:02:47 +0400
commitc64391f264b7658c00515173cca58f5b054af1a2 (patch)
tree67a403acfca8903a10bd45b86fe22488de476472 /drivers/usb/host/isp1760-hcd.c
parente08f6a2790aaf3563e7800399321c0fb9a6c6636 (diff)
downloadlinux-c64391f264b7658c00515173cca58f5b054af1a2.tar.xz
usb/isp1760: Fix race condition memory leak
This fixes a memory leak reported by Catalin Marinas: schedule_ptds() is called from isp1760_irq() and removes the qh from the controlqhs queue but ep->hcpriv still points to the qh and therefore it is not freed. Shortly after this, the isp1760_endpoint_disable() function sets ep->hcpriv to NULL and calls schedule_ptds() but since the corresponding qh is no longer in the queue, it is simply forgotten and reported by kmemleak. With this patch, the qh is always freed at endpoint_disable, instead, and the corresponding entry removed from the queue head list. While I was at it, I also replaced the lines in isp1760_endpoint_disable() that removed remaining qtds from the qh with a WARN_ON check for non-empty qh, in line with earlier comments from Alan Stern (linux-usb list, 2011-07-20). Signed-off-by: Arvid Brodin <arvid.brodin@enea.com> Tested-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host/isp1760-hcd.c')
-rw-r--r--drivers/usb/host/isp1760-hcd.c30
1 files changed, 12 insertions, 18 deletions
diff --git a/drivers/usb/host/isp1760-hcd.c b/drivers/usb/host/isp1760-hcd.c
index a760fbf18ebe..fc72d44bf787 100644
--- a/drivers/usb/host/isp1760-hcd.c
+++ b/drivers/usb/host/isp1760-hcd.c
@@ -937,7 +937,6 @@ void schedule_ptds(struct usb_hcd *hcd)
struct isp1760_hcd *priv;
struct isp1760_qh *qh, *qh_next;
struct list_head *ep_queue;
- struct usb_host_endpoint *ep;
LIST_HEAD(urb_list);
struct urb_listitem *urb_listitem, *urb_listitem_next;
int i;
@@ -955,17 +954,9 @@ void schedule_ptds(struct usb_hcd *hcd)
for (i = 0; i < QH_END; i++) {
ep_queue = &priv->qh_list[i];
list_for_each_entry_safe(qh, qh_next, ep_queue, qh_list) {
- ep = list_entry(qh->qtd_list.next, struct isp1760_qtd,
- qtd_list)->urb->ep;
collect_qtds(hcd, qh, &urb_list);
- if (list_empty(&qh->qtd_list)) {
+ if (list_empty(&qh->qtd_list))
list_del(&qh->qh_list);
- if (ep->hcpriv == NULL) {
- /* Endpoint has been disabled, so we
- can free the associated queue head. */
- qh_free(qh);
- }
- }
}
}
@@ -1708,8 +1699,8 @@ static void isp1760_endpoint_disable(struct usb_hcd *hcd,
{
struct isp1760_hcd *priv = hcd_to_priv(hcd);
unsigned long spinflags;
- struct isp1760_qh *qh;
- struct isp1760_qtd *qtd;
+ struct isp1760_qh *qh, *qh_iter;
+ int i;
spin_lock_irqsave(&priv->lock, spinflags);
@@ -1717,14 +1708,17 @@ static void isp1760_endpoint_disable(struct usb_hcd *hcd,
if (!qh)
goto out;
- list_for_each_entry(qtd, &qh->qtd_list, qtd_list)
- if (qtd->status != QTD_RETIRE) {
- dequeue_urb_from_qtd(hcd, qh, qtd);
- qtd->urb->status = -ECONNRESET;
- }
+ WARN_ON(!list_empty(&qh->qtd_list));
+ for (i = 0; i < QH_END; i++)
+ list_for_each_entry(qh_iter, &priv->qh_list[i], qh_list)
+ if (qh_iter == qh) {
+ list_del(&qh_iter->qh_list);
+ i = QH_END;
+ break;
+ }
+ qh_free(qh);
ep->hcpriv = NULL;
- /* Cannot free qh here since it will be parsed by schedule_ptds() */
schedule_ptds(hcd);