| From 0e6c7f746ea99089fb3263709075c20485a479ae Mon Sep 17 00:00:00 2001 |
| From: Kautuk Consul <consul.kautuk@gmail.com> |
| Date: Mon, 19 Sep 2011 16:53:12 -0700 |
| Subject: xhci-mem.c: Check for ring->first_seg != NULL |
| |
| From: Kautuk Consul <consul.kautuk@gmail.com> |
| |
| commit 0e6c7f746ea99089fb3263709075c20485a479ae upstream. |
| |
| There are 2 situations wherein the xhci_ring* might not get freed: |
| - When xhci_ring_alloc() -> xhci_segment_alloc() returns NULL and |
| we goto the fail: label in xhci_ring_alloc. In this case, the ring |
| will not get kfreed. |
| - When the num_segs argument to xhci_ring_alloc is passed as 0 and |
| we try to free the rung after that. |
| ( This doesn't really happen as of now in the code but we seem to |
| be entertaining num_segs=0 in xhci_ring_alloc ) |
| |
| This should be backported to kernels as old as 2.6.31. |
| |
| Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> |
| Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| drivers/usb/host/xhci-mem.c | 22 ++++++++++++---------- |
| 1 file changed, 12 insertions(+), 10 deletions(-) |
| |
| --- a/drivers/usb/host/xhci-mem.c |
| +++ b/drivers/usb/host/xhci-mem.c |
| @@ -110,18 +110,20 @@ void xhci_ring_free(struct xhci_hcd *xhc |
| struct xhci_segment *seg; |
| struct xhci_segment *first_seg; |
| |
| - if (!ring || !ring->first_seg) |
| + if (!ring) |
| return; |
| - first_seg = ring->first_seg; |
| - seg = first_seg->next; |
| - xhci_dbg(xhci, "Freeing ring at %p\n", ring); |
| - while (seg != first_seg) { |
| - struct xhci_segment *next = seg->next; |
| - xhci_segment_free(xhci, seg); |
| - seg = next; |
| + if (ring->first_seg) { |
| + first_seg = ring->first_seg; |
| + seg = first_seg->next; |
| + xhci_dbg(xhci, "Freeing ring at %p\n", ring); |
| + while (seg != first_seg) { |
| + struct xhci_segment *next = seg->next; |
| + xhci_segment_free(xhci, seg); |
| + seg = next; |
| + } |
| + xhci_segment_free(xhci, first_seg); |
| + ring->first_seg = NULL; |
| } |
| - xhci_segment_free(xhci, first_seg); |
| - ring->first_seg = NULL; |
| kfree(ring); |
| } |
| |