xhci-mem.c: Check for ring->first_seg != NULL
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>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 94a8b28..e4513ab 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -112,18 +112,20 @@
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);
}