This is a note to let you know that I've just added the patch titled

usb: gadget: don't dereference g until after it has been null checked

to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: usb-gadget-don-t-dereference-g-until-after-it-has-been-null-checked.patch and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Thu Feb 1 14:48:12 CET 2018

From: Colin Ian King colin.king@canonical.com Date: Tue, 14 Nov 2017 16:18:28 +0000 Subject: usb: gadget: don't dereference g until after it has been null checked

From: Colin Ian King colin.king@canonical.com

[ Upstream commit b2fc059fa549fe6881d4c1f8d698b0f50bcd16ec ]

Avoid dereferencing pointer g until after g has been sanity null checked; move the assignment of cdev much later when it is required into a more local scope.

Detected by CoverityScan, CID#1222135 ("Dereference before null check")

Fixes: b785ea7ce662 ("usb: gadget: composite: fix ep->maxburst initialization") Signed-off-by: Colin Ian King colin.king@canonical.com Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/gadget/composite.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -103,7 +103,6 @@ int config_ep_by_speed(struct usb_gadget struct usb_function *f, struct usb_ep *_ep) { - struct usb_composite_dev *cdev = get_gadget_data(g); struct usb_endpoint_descriptor *chosen_desc = NULL; struct usb_descriptor_header **speed_desc = NULL;

@@ -170,8 +169,12 @@ ep_found: _ep->maxburst = comp_desc->bMaxBurst + 1; break; default: - if (comp_desc->bMaxBurst != 0) + if (comp_desc->bMaxBurst != 0) { + struct usb_composite_dev *cdev; + + cdev = get_gadget_data(g); ERROR(cdev, "ep0 bMaxBurst must be 0\n"); + } _ep->maxburst = 1; break; }

Patches currently in stable-queue which might be from colin.king@canonical.com are

queue-3.18/usb-gadget-don-t-dereference-g-until-after-it-has-been-null-checked.patch