CVE-2025-38478

CVE Details

Release Date:	2025-07-28
Impact:	Moderate	What is this?

Description

In the Linux kernel, the following vulnerability has been resolved: comedi: Fix initialization of data for instructions that write to subdevice Some Comedi subdevice instruction handlers are known to access instruction data elements beyond the first `insn->n` elements in some cases. The `do_insn_ioctl()` and `do_insnlist_ioctl()` functions allocate at least `MIN_SAMPLES` (16) data elements to deal with this, but they do not initialize all of that. For Comedi instruction codes that write to the subdevice, the first `insn->n` data elements are copied from user-space, but the remaining elements are left uninitialized. That could be a problem if the subdevice instruction handler reads the uninitialized data. Ensure that the first `MIN_SAMPLES` elements are initialized before calling these instruction handlers, filling the uncopied elements with 0. For `do_insnlist_ioctl()`, the same data buffer elements are used for handling a list of instructions, so ensure the first `MIN_SAMPLES` elements are initialized for each instruction that writes to the subdevice.

See more information about CVE-2025-38478 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	5.5
Vector String:	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Version:	3.1
Attack Vector:	Local
Attack Complexity:	Low
Privileges Required:	Low
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	None
Integrity Impact:	None
Availability Impact:	High

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