Bug 2418893 (CVE-2025-40263) - CVE-2025-40263 kernel: Input: cros_ec_keyb - fix an invalid memory access
Summary: CVE-2025-40263 kernel: Input: cros_ec_keyb - fix an invalid memory access
Keywords:
Status: NEW
Alias: CVE-2025-40263
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
unspecified
unspecified
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-12-04 17:03 UTC by OSIDB Bzimport
Modified: 2025-12-19 14:19 UTC (History)
0 users

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2025-12-04 17:03:31 UTC
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.


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