This is a note to let you know that I've just added the patch titled
USB: Fix slab-out-of-bounds write in usb_get_bos_descriptor
to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From a03ff54460817c76105f81f3aa8ef655759ccc9a Mon Sep 17 00:00:00 2001
From: Alan Stern stern@rowland.harvard.edu Date: Mon, 13 May 2019 13:14:29 -0400 Subject: USB: Fix slab-out-of-bounds write in usb_get_bos_descriptor
The syzkaller USB fuzzer found a slab-out-of-bounds write bug in the USB core, caused by a failure to check the actual size of a BOS descriptor. This patch adds a check to make sure the descriptor is at least as large as it is supposed to be, so that the code doesn't inadvertently access memory beyond the end of the allocated region when assigning to dev->bos->desc->bNumDeviceCaps later on.
Signed-off-by: Alan Stern stern@rowland.harvard.edu Reported-and-tested-by: syzbot+71f1e64501a309fcc012@syzkaller.appspotmail.com CC: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/core/config.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 20ff036b4c22..9d6cb709ca7b 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -932,8 +932,8 @@ int usb_get_bos_descriptor(struct usb_device *dev)
/* Get BOS descriptor */ ret = usb_get_descriptor(dev, USB_DT_BOS, 0, bos, USB_DT_BOS_SIZE); - if (ret < USB_DT_BOS_SIZE) { - dev_err(ddev, "unable to get BOS descriptor\n"); + if (ret < USB_DT_BOS_SIZE || bos->bLength < USB_DT_BOS_SIZE) { + dev_err(ddev, "unable to get BOS descriptor or descriptor too short\n"); if (ret >= 0) ret = -ENOMSG; kfree(bos);