diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2019-05-13 13:14:29 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-21 10:08:55 +0200 |
| commit | a03ff54460817c76105f81f3aa8ef655759ccc9a (patch) | |
| tree | 0fe93a3cb19a1ae9375fe19933ccbfe5e0e2337e | |
| parent | a188339ca5a396acc588e5851ed7e19f66b0ebd9 (diff) | |
| download | linux-a03ff54460817c76105f81f3aa8ef655759ccc9a.tar.bz2 | |
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>
| -rw-r--r-- | drivers/usb/core/config.c | 4 |
1 files 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); |