n 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.
Configuration 1 (hide)
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Configuration 2 (hide)
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08 Jan 2026, 15:08
| Type | Values Removed | Values Added |
|---|---|---|
| CWE | NVD-CWE-noinfo | |
| CPE | cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
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| First Time |
Debian
Linux linux Kernel Linux Debian debian Linux |
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| References | () https://git.kernel.org/stable/c/7afba9221f70d4cbce0f417c558879cba0eb5e66 - Patch | |
| References | () https://git.kernel.org/stable/c/842f307a1d115b24f2bcb2415c4e344f11f55930 - Patch | |
| References | () https://git.kernel.org/stable/c/92352ed2f9ac422181e381c2430c2d0dfb46faa0 - Patch | |
| References | () https://git.kernel.org/stable/c/ab77e85bd3bc006ef40738f26f446a660813da44 - Patch | |
| References | () https://git.kernel.org/stable/c/ae8bc1f07bcb31b8636420e03d1f9c3df6219a2b - Patch | |
| References | () https://git.kernel.org/stable/c/dc0a2f142d655700db43de90cb6abf141b73d908 - Patch | |
| References | () https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html - Third Party Advisory, Mailing List | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.8 |
03 Nov 2025, 18:16
| Type | Values Removed | Values Added |
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| References |
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08 Sep 2025, 16:25
| Type | Values Removed | Values Added |
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| New CVE |
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