xhci: Don't free endpoints in xhci_mem_cleanup()

This patch fixes a few issues introduced in the recent fix
[f8a9e72d: USB: fix resource leak in xhci power loss path]

- The endpoints listed in bw table are just links and each entry is an
 array member of dev->eps[].  But the commit above adds a kfree() call
 to these instances, and thus it results in memory corruption.

- It clears only the first entry of rh_bw[], but there can be multiple
  ports.

- It'd be safer to clear the list_head of ep as well, not only
  removing from the list, as it's checked in
  xhci_discover_or_reset_device().

This patch should be backported to kernels as old as 3.2, that contain
the commit 839c817ce67178ca3c7c7ad534c571bba1e69ebe "xhci: Store
information about roothubs and TTs."

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reviewed-by: Oliver Neukum <oneukum@suse.de>
Cc: <stable@vger.kernel.org>

1 files changed, 14 insertions, 21 deletions

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 898dfc8bc520..77689bd64cac 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1772,17 +1772,9 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 {
         struct pci_dev  *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
         struct dev_info *dev_info, *next;
-        struct list_head *tt_list_head;
-        struct list_head *tt;
-        struct list_head *endpoints;
-        struct list_head *ep, *q;
-        struct xhci_tt_bw_info *tt_info;
-        struct xhci_interval_bw_table *bwt;
-        struct xhci_virt_ep *virt_ep;
-
         unsigned long   flags;
         int size;
-        int i;
+        int i, j, num_ports;
 
         /* Free the Event Ring Segment Table and the actual Event Ring */
         size = sizeof(struct xhci_erst_entry)*(xhci->erst.num_entries);
@@ -1841,21 +1833,22 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
         }
         spin_unlock_irqrestore(&xhci->lock, flags);
 
-        bwt = &xhci->rh_bw->bw_table;
-        for (i = 0; i < XHCI_MAX_INTERVAL; i++) {
-                endpoints = &bwt->interval_bw[i].endpoints;
-                list_for_each_safe(ep, q, endpoints) {
-                        virt_ep = list_entry(ep, struct xhci_virt_ep, bw_endpoint_list);
-                        list_del(&virt_ep->bw_endpoint_list);
-                        kfree(virt_ep);
+        num_ports = HCS_MAX_PORTS(xhci->hcs_params1);
+        for (i = 0; i < num_ports; i++) {
+                struct xhci_interval_bw_table *bwt = &xhci->rh_bw[i].bw_table;
+                for (j = 0; j < XHCI_MAX_INTERVAL; j++) {
+                        struct list_head *ep = &bwt->interval_bw[j].endpoints;
+                        while (!list_empty(ep))
+                                list_del_init(ep->next);
                 }
         }
 
-        tt_list_head = &xhci->rh_bw->tts;
-        list_for_each_safe(tt, q, tt_list_head) {
-                tt_info = list_entry(tt, struct xhci_tt_bw_info, tt_list);
-                list_del(tt);
-                kfree(tt_info);
+        for (i = 0; i < num_ports; i++) {
+                struct xhci_tt_bw_info *tt, *n;
+                list_for_each_entry_safe(tt, n, &xhci->rh_bw[i].tts, tt_list) {
+                        list_del(&tt->tt_list);
+                        kfree(tt);
+                }
         }
 
         xhci->num_usb2_ports = 0;