[ 30/61] xhci: Dont free endpoints in xhci_mem_cleanup()

From: Greg KH
Date: Wed Jun 20 2012 - 14:22:39 EST


3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Takashi Iwai <tiwai@xxxxxxx>

commit 32f1d2c536d0c26c5814cb0e6a0606c42d02fac1 upstream.

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@xxxxxxx>
Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Reviewed-by: Oliver Neukum <oneukum@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/host/xhci-mem.c | 35 ++++++++++++++---------------------
1 file changed, 14 insertions(+), 21 deletions(-)

--- 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 *x
{
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);
@@ -1839,21 +1831,22 @@ void xhci_mem_cleanup(struct xhci_hcd *x
}
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;


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