| Message ID | 1439297784-31464-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 8936211b161d..5c68f227b8bf 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -1431,10 +1431,10 @@ int xhci_endpoint_init(struct xhci_hcd *xhci, /* Attempt to use the ring cache */ if (virt_dev->num_rings_cached == 0) return -ENOMEM; + virt_dev->num_rings_cached--; virt_dev->eps[ep_index].new_ring = virt_dev->ring_cache[virt_dev->num_rings_cached]; virt_dev->ring_cache[virt_dev->num_rings_cached] = NULL; - virt_dev->num_rings_cached--; xhci_reinit_cached_ring(xhci, virt_dev->eps[ep_index].new_ring, 1, type); }
This is a note to let you know that I have just added a patch titled usb: xhci: Bugfix for NULL pointer deference in xhci_endpoint_init() function to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt16. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From cc593f964a270635e1947b4f64b89380ece3dcd4 Mon Sep 17 00:00:00 2001 From: AMAN DEEP <aman.deep@samsung.com> Date: Tue, 21 Jul 2015 17:20:27 +0300 Subject: usb: xhci: Bugfix for NULL pointer deference in xhci_endpoint_init() function commit 3496810663922617d4b706ef2780c279252ddd6a upstream. virt_dev->num_cached_rings counts on freed ring and is not updated correctly. In xhci_free_or_cache_endpoint_ring() function, the free ring is added into cache and then num_rings_cache is incremented as below: virt_dev->ring_cache[rings_cached] = virt_dev->eps[ep_index].ring; virt_dev->num_rings_cached++; here, free ring pointer is added to a current index and then index is incremented. So current index always points to empty location in the ring cache. For getting available free ring, current index should be decremented first and then corresponding ring buffer value should be taken from ring cache. But In function xhci_endpoint_init(), the num_rings_cached index is accessed before decrement. virt_dev->eps[ep_index].new_ring = virt_dev->ring_cache[virt_dev->num_rings_cached]; virt_dev->ring_cache[virt_dev->num_rings_cached] = NULL; virt_dev->num_rings_cached--; This is bug in manipulating the index of ring cache. And it should be as below: virt_dev->num_rings_cached--; virt_dev->eps[ep_index].new_ring = virt_dev->ring_cache[virt_dev->num_rings_cached]; virt_dev->ring_cache[virt_dev->num_rings_cached] = NULL; Signed-off-by: Aman Deep <aman.deep@samsung.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/usb/host/xhci-mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)