CVE-2025-39686

In the Linux kernel, the following vulnerability has been resolved: comedi: Make insn_rw_emulate_bits() do insn->n samples The `insn_rw_emulate_bits()` function is used as a default handler for `INSN_READ` instructions for subdevices that have a handler for `INSN_BITS` but not for `INSN_READ`. Similarly, it is used as a default handler for `INSN_WRITE` instructions for subdevices that have a handler for `INSN_BITS` but not for `INSN_WRITE`. It works by emulating the `INSN_READ` or `INSN_WRITE` instruction handling with a constructed `INSN_BITS` instruction. However, `INSN_READ` and `INSN_WRITE` instructions are supposed to be able read or write multiple samples, indicated by the `insn->n` value, but `insn_rw_emulate_bits()` currently only handles a single sample. For `INSN_READ`, the comedi core will copy `insn->n` samples back to user-space. (That triggered KASAN kernel-infoleak errors when `insn->n` was greater than 1, but that is being fixed more generally elsewhere in the comedi core.) Make `insn_rw_emulate_bits()` either handle `insn->n` samples, or return an error, to conform to the general expectation for `INSN_READ` and `INSN_WRITE` handlers.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*

Configuration 2 (hide)

cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

History

08 Jan 2026, 15:08

Type Values Removed Values Added
CWE NVD-CWE-noinfo
References () https://git.kernel.org/stable/c/7afba9221f70d4cbce0f417c558879cba0eb5e66 - () https://git.kernel.org/stable/c/7afba9221f70d4cbce0f417c558879cba0eb5e66 - Patch
References () https://git.kernel.org/stable/c/842f307a1d115b24f2bcb2415c4e344f11f55930 - () https://git.kernel.org/stable/c/842f307a1d115b24f2bcb2415c4e344f11f55930 - Patch
References () https://git.kernel.org/stable/c/92352ed2f9ac422181e381c2430c2d0dfb46faa0 - () https://git.kernel.org/stable/c/92352ed2f9ac422181e381c2430c2d0dfb46faa0 - Patch
References () https://git.kernel.org/stable/c/ab77e85bd3bc006ef40738f26f446a660813da44 - () https://git.kernel.org/stable/c/ab77e85bd3bc006ef40738f26f446a660813da44 - Patch
References () https://git.kernel.org/stable/c/ae8bc1f07bcb31b8636420e03d1f9c3df6219a2b - () https://git.kernel.org/stable/c/ae8bc1f07bcb31b8636420e03d1f9c3df6219a2b - Patch
References () https://git.kernel.org/stable/c/dc0a2f142d655700db43de90cb6abf141b73d908 - () https://git.kernel.org/stable/c/dc0a2f142d655700db43de90cb6abf141b73d908 - Patch
References () https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html - () https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html - Third Party Advisory, Mailing List
CPE cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8
First Time Linux
Debian
Debian debian Linux
Linux linux Kernel

03 Nov 2025, 18:16

Type Values Removed Values Added
References
  • () https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html -

05 Sep 2025, 18:15

Type Values Removed Values Added
New CVE

Information

Published : 2025-09-05 18:15

Updated : 2026-01-08 15:08


NVD link : CVE-2025-39686

Mitre link : CVE-2025-39686

CVE.ORG link : CVE-2025-39686


JSON object : View

Products Affected

debian

  • debian_linux

linux

  • linux_kernel