CVE-2025-38478

high

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.

References

https://git.kernel.org/stable/c/fe8713fb4e4e82a4f91910d9a41bf0613e69a0b9

https://git.kernel.org/stable/c/d3436638738ace8f101af7bdee2eae1bc38e9b29

https://git.kernel.org/stable/c/c42116dc70af6664526f7aa82cf937824ab42649

https://git.kernel.org/stable/c/673ee92bd2d31055bca98a1d96b653f5284289c4

https://git.kernel.org/stable/c/46d8c744136ce2454aa4c35c138cc06817f92b8e

Details

Source: Mitre, NVD

Published: 2025-07-28

Updated: 2025-07-29

Risk Information

CVSS v2

Base Score: 6.1

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:C

Severity: Medium

CVSS v3

Base Score: 7.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00018