Entreprise française de cybersécurité depuis 2004
☎ 03 60 47 09 81 - info@securiteinfo.com
☎ 03 60 47 09 81 - info@securiteinfo.com
In the Linux kernel, the following vulnerability has been resolved:HID: asus: fix UAF via HID_CLAIMED_INPUT validationAfter hid_hw_start() is called hidinput_connect() will eventually becalled to set up the device with the input layer since theHID_CONNECT_DEFAULT connect mask is used. During hidinput_connect()all input and output reports are processed and corresponding hid_inputsare allocated and configured via hidinput_configure_usages(). Thisprocess involves slot tagging report fields and configuring usagesby setting relevant bits in the capability bitmaps. However it is possiblethat the capability bitmaps are not set at all leading to the subsequenthidinput_has_been_populated() check to fail leading to the freeing of thehid_input and the underlying input device.This becomes problematic because a malicious HID device like aASUS ROG N-Key keyboard can trigger the above scenario via aspecially crafted descriptor which then leads to a user-after-freewhen the name of the freed input device is written to later on afterhid_hw_start(). Below, report 93 intentionally utilises theHID_UP_UNDEFINED Usage Page which is skipped during usageconfiguration, leading to the frees.0x05, 0x0D, // Usage Page (Digitizer)0x09, 0x05, // Usage (Touch Pad)0xA1, 0x01, // Collection (Application)0x85, 0x0D, // Report ID (13)0x06, 0x00, 0xFF, // Usage Page (Vendor Defined 0xFF00)0x09, 0xC5, // Usage (0xC5)0x15, 0x00, // Logical Minimum (0)0x26, 0xFF, 0x00, // Logical Maximum (255)0x75, 0x08, // Report Size (8)0x95, 0x04, // Report Count (4)0xB1, 0x02, // Feature (Data,Var,Abs)0x85, 0x5D, // Report ID (93)0x06, 0x00, 0x00, // Usage Page (Undefined)0x09, 0x01, // Usage (0x01)0x15, 0x00, // Logical Minimum (0)0x26, 0xFF, 0x00, // Logical Maximum (255)0x75, 0x08, // Report Size (8)0x95, 0x1B, // Report Count (27)0x81, 0x02, // Input (Data,Var,Abs)0xC0, // End CollectionBelow is the KASAN splat after triggering the UAF:[ 21.672709] ==================================================================[ 21.673700] BUG: KASAN: slab-use-after-free in asus_probe+0xeeb/0xf80[ 21.673700] Write of size 8 at addr ffff88810a0ac000 by task kworker/1:2/54[ 21.673700][ 21.673700] CPU: 1 UID: 0 PID: 54 Comm: kworker/1:2 Not tainted 6.16.0-rc4-g9773391cf4dd-dirty #36 PREEMPT(voluntary)[ 21.673700] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014[ 21.673700] Call Trace:[ 21.673700]
No PoCs from references.
- https://github.com/w4zu/Debian_security