[PATCH 3.13 057/163] usb: xhci: Fix OOPS in xhci error handling code

Kamal Mostafa kamal at canonical.com
Thu Oct 9 21:01:22 UTC 2014 -stable review patch.  If anyone has any objections, please let me know.


From: Al Cooper <alcooperx at gmail.com>

commit 0eda06c7c17ae48d7db69beef57f6e2b20bc3c72 upstream.

The xhci driver will OOPS on resume from S2/S3 if dma_alloc_coherent()
is out of memory. This is a result of two things:
1. xhci_mem_cleanup() in xhci-mem.c free's xhci->lpm_command if
it's not NULL, but doesn't set it to NULL after the free.
2. xhci_mem_cleanup() is called twice on resume, once for normal
restart and once from xhci_mem_init() if dma_alloc_coherent() fails,
resulting in a free of xhci->lpm_command that has already been freed.
The fix is to set xhci->lpm_command to NULL after freeing it.

Signed-off-by: Al Cooper <alcooperx at gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman at linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
 drivers/usb/host/xhci-mem.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 837c333..06d0d1e 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1711,6 +1711,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 	if (xhci->lpm_command)
 		xhci_free_command(xhci, xhci->lpm_command);
+	xhci->lpm_command = NULL;
 	xhci->cmd_ring_reserved_trbs = 0;
 	if (xhci->cmd_ring)
 		xhci_ring_free(xhci, xhci->cmd_ring);

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