CVE-2025-40263 Input: cros_ec_keyb - fix an invalid memory access
A null pointer dereference in the Chrome OS EC keyboard driver causes a kernel crash when processing specific events without proper initialization.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-40263?
CVE-2025-40263 is a vulnerability in Linux, published on 4 Dec 2025. 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:
Input: cros_ec_keyb - fix an invalid memory access
If cros_ec_keyb_register_matrix() isn't called (due to `buttons_switches_only`) in cros_ec_keyb_probe(), `ckdev->idev` remains NULL. An invalid memory access is observed in cros_ec_keyb_process() when receiving an EC_MKBP_EVENT_KEY_MATRIX event in cros_ec_keyb_work() in such case.
Unable to handle kernel read from unreadable memory at virtual address 0000000000000028 ... x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: input_event cros_ec_keyb_work blocking_notifier_call_chain ec_irq_thread
It's still unknown about why the kernel receives such malformed event, in any cases, the kernel shouldn't access `ckdev->idev` and friends if the driver doesn't intend to initialize them.
Which versions are affected by CVE-2025-40263?
How do I fix CVE-2025-40263?
Apply the vendor's patch.
Is CVE-2025-40263 being exploited?
There is no known exploitation of CVE-2025-40263 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40263, DEBIAN-CVE-2025-40263, GHSA-r3v3-c3jq-3938, ROOT-OS-DEBIAN-12-CVE-2025-40263, ROOT-OS-DEBIAN-13-CVE-2025-40263, ROOT-OS-UBUNTU-2204-CVE-2025-40263 and 2 more.