Messages in this thread Patch in this message | | | Date | Wed, 02 Nov 2011 15:26:38 -0700 | From | Greg KH <> | Subject | [054/101] xhci-mem.c: Check for ring->first_seg != NULL |
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2.6.33-longterm review patch. If anyone has any objections, please let us know.
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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); }
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