xenbus: Use kref to track req lifetime (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.24 % · percentile 15 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
Description
In the Linux kernel, the following vulnerability has been resolved: xenbus: Use kref to track req lifetime Marek reported seeing a NULL pointer fault in the xenbus_thread callstack: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: e030:__wake_up_common+0x4c/0x180 Call Trace: <TASK> __wake_up_common_lock+0x82/0xd0 process_msg+0x18e/0x2f0 xenbus_thread+0x165/0x1c0 process_msg+0x18e is req->cb(req). req->cb is set to xs_wake_up(), a thin wrapper around wake_up(), or xenbus_dev_queue_reply(). It seems like it was xs_wake_up() in this case. It seems like req may have woken up the xs_wait_for_reply(), which kfree()ed the req. When xenbus_thread resumes, it faults on the zero-ed data. Linux Device Drivers 2nd edition states: "Normally, a wake_up call can cause an immediate reschedule to happen, meaning that other processes might run before wake_up returns." ... which would match the behaviour observed. Change to keeping two krefs on each request. One for the caller, and one for xenbus_thread. Each will kref_put() when finished, and the last will free it. This use of kref matches the description in Documentation/core-api/kref.rst
Weaknesses (CWE)
- CWE-476 — NULL Pointer Dereference
References
- https://git.kernel.org/stable/c/0e94a246bb6d9538010b6c02d2b1d4717a97b2e5
- https://git.kernel.org/stable/c/f1bcac367bc95631afbb918348f30dec887d0e1b
- https://git.kernel.org/stable/c/4d260a5558df4650eb87bc41b2c9ac2d6b2ba447
- https://git.kernel.org/stable/c/8b02f85e84dc6f7c150cef40ddb69af5a25659e5
- https://git.kernel.org/stable/c/cbfaf46b88a4c01b64c4186cdccd766c19ae644c
- https://git.kernel.org/stable/c/8e9c8a0393b5f85f1820c565ab8105660f4e8f92
- https://git.kernel.org/stable/c/2466b0f66795c3c426cacc8998499f38031dbb59
- https://git.kernel.org/stable/c/1f0304dfd9d217c2f8b04a9ef4b3258a66eedd27
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | Linux |
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | NVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary) |
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2025-15894
- GCVE · GCVE-0-2025-37949
CERT-FR advisories
- CERTFR-2026-AVI-0246 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0227 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0218 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0194 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0169 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0894 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0758 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0756 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0743 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0721 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0697 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0670 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0650 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0625 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0529 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0509 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0464 — Multiples vulnérabilités dans le noyau Linux de Debian · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 4.11 < 5.4.294cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.5 < 5.10.238cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.11 < 5.15.183cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.16 < 6.1.139cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.2 < 6.6.91cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.29cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.14.7cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:*cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected fd8aa9095a95c02dcc35540a263267c29b8fda9d < 0e94a246bb6d9538010b6c02d2b1d4717a97b2e5 ; affected fd8aa9095a95c02dcc35540a263267c29b8fda9d < f1bcac367bc95631afbb918348f30dec887d0e1b ; affected fd8aa9095a95c02dcc35540a263267c29b8fda9d < 4d260a5558df4650eb87bc41b2c9ac2d6b2ba447 ; affected fd8aa9095a95c02dcc35540a263267c29b8fda9d < 8b02f85e84dc6f7c150cef40ddb69af5a25659e5 ; affected fd8aa9095a95c02dcc35540a263267c29b8fda9d < cbfaf46b88a4c01b64c4186cdccd766c19ae644c ; affected fd8aa9095a95c02dcc35540a263267c29b8fda9d < 8e9c8a0393b5f85f1820c565ab8105660f4e8f92 |
| Linux · Linux | affected 4.11 ; unaffected 0 < 4.11 ; unaffected 5.4.294 ≤ 5.4.* ; unaffected 5.10.238 ≤ 5.10.* ; unaffected 5.15.183 ≤ 5.15.* ; unaffected 6.1.139 ≤ 6.1.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |