CVE-2023-52478 HID: logitech-hidpp: Fix kernel crash on receiver USB disconnect

What is CVE-2023-52478?

CVE-2023-52478 is a high-severity vulnerability in Linux kernel, published on 29 Feb 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

HID: logitech-hidpp: Fix kernel crash on receiver USB disconnect

hidpp_connect_event() has *four* time-of-check vs time-of-use (TOCTOU) races when it races with itself.

hidpp_connect_event() primarily runs from a workqueue but it also runs on probe() and if a "device-connected" packet is received by the hw when the thread running hidpp_connect_event() from probe() is waiting on the hw, then a second thread running hidpp_connect_event() will be started from the workqueue.

This opens the following races (note the below code is simplified):

1. Retrieving + printing the protocol (harmless race):

if (!hidpp->protocol_major) { hidpp_root_get_protocol_version() hidpp->protocol_major = response.rap.params[0]; }

We can actually see this race hit in the dmesg in the abrt output attached to rhbz#2227968:

[ 3064.624215] logitech-hidpp-device 0003:046D:4071.0049: HID++ 4.5 device connected. [ 3064.658184] logitech-hidpp-device 0003:046D:4071.0049: HID++ 4.5 device connected.

Testing with extra logging added has shown that after this the 2 threads take turn grabbing the hw access mutex (send_mutex) so they ping-pong through all the other TOCTOU cases managing to hit all of them:

2. Updating the name to the HIDPP name (harmless race):

if (hidpp->name == hdev->name) { ... hidpp->name = new_name; }

3. Initializing the power_supply class for the battery (problematic!):

hidpp_initialize_battery() { if (hidpp->battery.ps) return 0;

probe_battery(); /* Blocks, threads take turns executing this */

hidpp->battery.desc.properties = devm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL);

hidpp->battery.ps = devm_power_supply_register(&hidpp->hid_dev->dev, &hidpp->battery.desc, cfg); }

4. Creating delayed input_device (potentially problematic):

if (hidpp->delayed_input) return;

hidpp->delayed_input = hidpp_allocate_input(hdev);

The really big problem here is 3. Hitting the race leads to the following sequence:

hidpp->battery.desc.properties = devm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL);

hidpp->battery.ps = devm_power_supply_register(&hidpp->hid_dev->dev, &hidpp->battery.desc, cfg);

...

hidpp->battery.desc.properties = devm_kmemdup(dev, hidpp_battery_props, cnt, GFP_KERNEL);

hidpp->battery.ps = devm_power_supply_register(&hidpp->hid_dev->dev, &hidpp->battery.desc, cfg);

So now we have registered 2 power supplies for the same battery, which looks a bit weird from userspace's pov but this is not even the really big problem.

Notice how:

1. This is all devm-maganaged 2. The hidpp->battery.desc struct is shared between the 2 power supplies 3. hidpp->battery.desc.properties points to the result from the second devm_kmemdup()

This causes a use after free scenario on USB disconnect of the receiver: 1. The last registered power supply class device gets unregistered 2. The memory from the last devm_kmemdup() call gets freed, hidpp->battery.desc.properties now points to freed memory 3. The first registered power supply class device gets unregistered, this involves sending a remove uevent to userspace which invokes power_supply_uevent() to fill the uevent data 4. power_supply_uevent() uses hidpp->battery.desc.properties which now points to freed memory leading to backtraces like this one:

Sep 22 20:01:35 eric kernel: BUG: unable to handle page fault for address: ffffb2140e017f08 ... Sep 22 20:01:35 eric kernel: Workqueue: usb_hub_wq hub_event Sep 22 20:01:35 eric kernel: RIP: 0010:power_supply_uevent+0xee/0x1d0 ... Sep 22 20:01:35 eric kernel: ? asm_exc_page_fault+0x26/0x30 Sep 22 20:01:35 eric kernel: ? power_supply_uevent+0xee/0x1d0 Sep 22 20:01:35 eric kernel: ? power_supply_uevent+0x10d/0x1d0 Sep 22 20:01:35 eric kernel: dev_uevent+0x10f/0x2d0 Sep 22 20:01:35 eric kernel: kobject_uevent_env+0x291/0x680 Sep 22 20:01:35 eric kernel: ---truncated---

Weakness: CWE-367

Which versions are affected by CVE-2023-52478?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2023-52478?

Apply the vendor's patch.

Is CVE-2023-52478 being exploited?

There is no known exploitation of CVE-2023-52478 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2023-52478, DEBIAN-CVE-2023-52478, GHSA-f7hm-xqp4-h2q8, UBUNTU-CVE-2023-52478.