From 0e6c7f746ea99089fb3263709075c20485a479ae Mon Sep 17 00:00:00 2001 From: Kautuk Consul Date: Mon, 19 Sep 2011 16:53:12 -0700 Subject: [PATCH] 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 Signed-off-by: Sarah Sharp Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-mem.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 94a8b28d602e..e4513ab015b4 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -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); } -- 2.30.2