On Wed, Sep 4, 2013 at 6:37 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: > A HID device could send a malicious output report that would cause the > lenovo-tpkbd HID driver to write just beyond the output report allocation > during initialization, causing a heap overflow: > > [ 76.109807] usb 1-1: New USB device found, idVendor=17ef, idProduct=6009 > ... > [ 80.462540] BUG kmalloc-192 (Tainted: G W ): Redzone overwritten > > CVE-2013-2894 > > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> > Cc: stable@xxxxxxxxxx > --- As mentioned by Josh on the previous thread, this patch triggers a bug for the users: https://bugzilla.redhat.com/show_bug.cgi?id=1003998 I am writing the comments I have given the bug: > drivers/hid/hid-lenovo-tpkbd.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/hid/hid-lenovo-tpkbd.c b/drivers/hid/hid-lenovo-tpkbd.c > index 07837f5..f458e76 100644 > --- a/drivers/hid/hid-lenovo-tpkbd.c > +++ b/drivers/hid/hid-lenovo-tpkbd.c > @@ -339,7 +339,15 @@ static int tpkbd_probe_tp(struct hid_device *hdev) > struct tpkbd_data_pointer *data_pointer; > size_t name_sz = strlen(dev_name(dev)) + 16; > char *name_mute, *name_micmute; > - int ret; > + int i, ret; > + > + /* Validate required reports. */ > + for (i = 0; i < 4; i++) { > + if (!hid_validate_values(hdev, HID_OUTPUT_REPORT, 4, i, 1)) The report descriptor shows that the report ID 4 is a FEATURE, not an OUTPUT. > + return -ENODEV; There is a problem in the probe() function when tpkbd_probe_tp() fails: it directly bails out instead of calling hid_hw_stop(), thus, the input devices are still there while nobody has a pointer to them. This way, ODEBUG is triggered. But this should be address in an other patch I would say. Cheers, Benjamin > + } > + if (!hid_validate_values(hdev, HID_OUTPUT_REPORT, 3, 0, 2)) > + return -ENODEV; > > if (sysfs_create_group(&hdev->dev.kobj, > &tpkbd_attr_group_pointer)) { > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-input" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
