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authorMichaƂ Pecio <michal.pecio@gmail.com>2016-06-07 10:34:45 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-06-08 05:15:25 (GMT)
commitc66f59ee5050447b3da92d36f5385a847990a894 (patch)
treef2c31d3fd017c24398a1e9db589a05373342fe85 /drivers/usb
parent7b2c17f829545df27a910e8d82e133c21c9a8c9c (diff)
downloadlinux-c66f59ee5050447b3da92d36f5385a847990a894.tar.xz
USB: OHCI: Don't mark EDs as ED_OPER if scheduling fails
Since ed_schedule begins with marking the ED as "operational", the ED may be left in such state even if scheduling actually fails. This allows future submission attempts to smuggle this ED to the hardware behind the scheduler's back and without linking it to the ohci->eds_in_use list. The former causes bandwidth saturation and data loss on isoc endpoints, the latter crashes the kernel when attempt is made to unlink such ED from this list. Fix ed_schedule to update ED state only on successful return. Signed-off-by: Michal Pecio <michal.pecio@gmail.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/host/ohci-q.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/usb/host/ohci-q.c b/drivers/usb/host/ohci-q.c
index d029bbe..641fed6 100644
--- a/drivers/usb/host/ohci-q.c
+++ b/drivers/usb/host/ohci-q.c
@@ -183,7 +183,6 @@ static int ed_schedule (struct ohci_hcd *ohci, struct ed *ed)
{
int branch;
- ed->state = ED_OPER;
ed->ed_prev = NULL;
ed->ed_next = NULL;
ed->hwNextED = 0;
@@ -259,6 +258,8 @@ static int ed_schedule (struct ohci_hcd *ohci, struct ed *ed)
/* the HC may not see the schedule updates yet, but if it does
* then they'll be properly ordered.
*/
+
+ ed->state = ED_OPER;
return 0;
}