CVE-2024-56545 HID: hyperv: streamline driver probe to avoid devres issues
A missing devres group allocation in the Hyper-V HID driver causes a kernel warning and potential crash when the module is unloaded.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-56545?
CVE-2024-56545 is a medium-severity vulnerability in Linux kernel, published on 27 Dec 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: hyperv: streamline driver probe to avoid devres issues
It was found that unloading 'hid_hyperv' module results in a devres complaint:
... hv_vmbus: unregistering driver hid_hyperv ------------[ cut here ]------------ WARNING: CPU: 2 PID: 3983 at drivers/base/devres.c:691 devres_release_group+0x1f2/0x2c0 ... Call Trace: <TASK> ? devres_release_group+0x1f2/0x2c0 ? __warn+0xd1/0x1c0 ? devres_release_group+0x1f2/0x2c0 ? report_bug+0x32a/0x3c0 ? handle_bug+0x53/0xa0 ? exc_invalid_op+0x18/0x50 ? asm_exc_invalid_op+0x1a/0x20 ? devres_release_group+0x1f2/0x2c0 ? devres_release_group+0x90/0x2c0 ? rcu_is_watching+0x15/0xb0 ? __pfx_devres_release_group+0x10/0x10 hid_device_remove+0xf5/0x220 device_release_driver_internal+0x371/0x540 ? klist_put+0xf3/0x170 bus_remove_device+0x1f1/0x3f0 device_del+0x33f/0x8c0 ? __pfx_device_del+0x10/0x10 ? cleanup_srcu_struct+0x337/0x500 hid_destroy_device+0xc8/0x130 mousevsc_remove+0xd2/0x1d0 [hid_hyperv] device_release_driver_internal+0x371/0x540 driver_detach+0xc5/0x180 bus_remove_driver+0x11e/0x2a0 ? __mutex_unlock_slowpath+0x160/0x5e0 vmbus_driver_unregister+0x62/0x2b0 [hv_vmbus] ...
And the issue seems to be that the corresponding devres group is not allocated. Normally, devres_open_group() is called from __hid_device_probe() but Hyper-V HID driver overrides 'hid_dev->driver' with 'mousevsc_hid_driver' stub and basically re-implements __hid_device_probe() by calling hid_parse() and hid_hw_start() but not devres_open_group(). hid_device_probe() does not call __hid_device_probe() for it. Later, when the driver is removed, hid_device_remove() calls devres_release_group() as it doesn't check whether hdev->driver was initially overridden or not.
The issue seems to be related to the commit 62c68e7cee33 ("HID: ensure timely release of driver-allocated resources") but the commit itself seems to be correct.
Fix the issue by dropping the 'hid_dev->driver' override and using hid_register_driver()/hid_unregister_driver() instead. Alternatively, it would have been possible to rely on the default handling but HID_CONNECT_DEFAULT implies HID_CONNECT_HIDRAW and it doesn't seem to work for mousevsc as-is.
Which versions are affected by CVE-2024-56545?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-56545?
Apply the vendor's patch.
Is CVE-2024-56545 being exploited?
There is no known exploitation of CVE-2024-56545 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-56545, DEBIAN-CVE-2024-56545, GHSA-r47r-3q5h-27v7, UBUNTU-CVE-2024-56545.