This is a note to let you know that I've just added the patch titled
USB: EHCI: bugfix: urb->hcpriv should not be NULL
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-ehci-bugfix-urb-hcpriv-should-not-be-null.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b9678188b8f570d5c620dd3822485319c38a3709 Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Date: Thu, 8 Nov 2012 10:17:01 -0500
Subject: USB: EHCI: bugfix: urb->hcpriv should not be NULL
From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
commit 2656a9abcf1ec8dd5fee6a75d6997a0f2fa0094e upstream.
This patch (as1632b) fixes a bug in ehci-hcd. The USB core uses
urb->hcpriv to determine whether or not an URB is active; host
controller drivers are supposed to set this pointer to a non-NULL
value when an URB is queued. However ehci-hcd sets it to NULL for
isochronous URBs, which defeats the check in usbcore.
In itself this isn't a big deal. But people have recently found that
certain sequences of actions will cause the snd-usb-audio driver to
reuse URBs without waiting for them to complete. In the absence of
proper checking by usbcore, the URBs get added to their endpoint list
twice. This leads to list corruption and a system freeze.
The patch makes ehci-hcd assign a meaningful value to urb->hcpriv for
isochronous URBs. Improving robustness always helps.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-by: Artem S. Tashkinov <t.artem@xxxxxxxxx>
Reported-by: Christof Meerwald <cmeerw@xxxxxxxxxx>
[bwh: Backported to 3.2:
- Adjust context
- Also use usb_pipetype() to work out whether we should call qh_put()]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/host/ehci-q.c | 16 ++++++----------
drivers/usb/host/ehci-sched.c | 4 ++--
2 files changed, 8 insertions(+), 12 deletions(-)
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -264,18 +264,14 @@ ehci_urb_done(struct ehci_hcd *ehci, str
__releases(ehci->lock)
__acquires(ehci->lock)
{
- if (likely (urb->hcpriv != NULL)) {
- struct ehci_qh *qh = (struct ehci_qh *) urb->hcpriv;
-
- /* S-mask in a QH means it's an interrupt urb */
- if ((qh->hw->hw_info2 & cpu_to_hc32(ehci, QH_SMASK)) != 0) {
-
- /* ... update hc-wide periodic stats (for usbfs) */
- ehci_to_hcd(ehci)->self.bandwidth_int_reqs--;
- }
- qh_put (qh);
+ if (usb_pipetype(urb->pipe) == PIPE_INTERRUPT) {
+ /* ... update hc-wide periodic stats */
+ ehci_to_hcd(ehci)->self.bandwidth_int_reqs--;
}
+ if (usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS)
+ qh_put((struct ehci_qh *) urb->hcpriv);
+
if (unlikely(urb->unlinked)) {
COUNT(ehci->stats.unlink);
} else {
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1684,7 +1684,7 @@ itd_link_urb (
/* don't need that schedule data any more */
iso_sched_free (stream, iso_sched);
- urb->hcpriv = NULL;
+ urb->hcpriv = stream;
timer_action (ehci, TIMER_IO_WATCHDOG);
return enable_periodic(ehci);
@@ -2094,7 +2094,7 @@ sitd_link_urb (
/* don't need that schedule data any more */
iso_sched_free (stream, sched);
- urb->hcpriv = NULL;
+ urb->hcpriv = stream;
timer_action (ehci, TIMER_IO_WATCHDOG);
return enable_periodic(ehci);
Patches currently in stable-queue which might be from stern@xxxxxxxxxxxxxxxxxxx are
queue-3.4/usb-add-usb_quirk_reset_resume-for-all-logitech-uvc-webcams.patch
queue-3.4/usb-ehci-bugfix-urb-hcpriv-should-not-be-null.patch
queue-3.4/usb-add-quirk-detection-based-on-interface-information.patch
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