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>
This commit is contained in:
Kautuk Consul 2011-09-19 16:53:12 -07:00 committed by Greg Kroah-Hartman
parent 10d674a82e
commit 0e6c7f746e
1 changed files with 12 additions and 10 deletions

View File

@ -112,18 +112,20 @@ void xhci_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring)
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);
}