Vulnerability-Lookup

BDU:2026-09205 (CVE-2025-39779)

Vulnerability from fstec – Published: 2026-07-03 – Updated: 2026-07-03 – View on bdu.fstec.ru Fixed

Title

Уязвимость функции btrfs_subpage_set_writeback() модуля fs/btrfs/subpage.c файловой системы btrfs ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Summary

Уязвимость функции btrfs_subpage_set_writeback() модуля fs/btrfs/subpage.c файловой системы btrfs ядра операционной системы Linux связана с неконтролируемым достижимым утверждением. Эксплуатация уязвимости может позволить нарушителю вызвать отказ в обслуживании

Severity

4.6 (Medium) CVSS 2.0


                      
                        AV:L/AC:L/Au:S/C:N/I:N/A:C

5.5 (Medium) CVSS 3.1


                      
                        CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Class

Code vulnerability

Status

Confirmed by the vendor

Exploitation

Data structure manipulation

Incidents

Being clarified

Remediation

Software update

CWE

CWE-617 - Доступная функция assert()

Aliases

CVE-2025-39779

References

10 references

URL
https://www.cve.org/CVERecord?id=CVE-2025-39779
https://git.kernel.org/stable/c/3d61136945a7008fc90d013c3c67007ce0c96131
https://git.kernel.org/stable/c/bce7a5c77a1e7a759e227b7713dde18c52da4759
https://git.kernel.org/linus/b1511360c8ac882b0c52caa263620538e8d73220
https://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.44
https://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.16.4
https://www.suse.com/security/cve/CVE-2025-39779.html
https://security-tracker.debian.org/tracker/CVE-2025-39779
https://ubuntu.com/security/CVE-2025-39779
https://lore.kernel.org/linux-cve-announce/2025091148-CVE-2025-39779-7d77@gregkh/

Impacted products

7 products from 3 vendors

Vendors

Canonical Ltd., Сообщество свободного программного обеспечения, Novell Inc.

Products

Ubuntu, Debian GNU/Linux, SUSE Linux Enterprise Server for SAP Applications, Suse Linux Enterprise Server, OpenSUSE Leap, SUSE Linux Micro, Linux

Versions

22.04 LTS (Ubuntu), 24.04 LTS (Ubuntu), 13 (Debian GNU/Linux), 16.0 (SUSE Linux Enterprise Server for SAP Applications), 16.0 (Suse Linux Enterprise Server), 16.0 (OpenSUSE Leap), 6.2 (SUSE Linux Micro), от 6.13 до 6.16.3 включительно (Linux), от 5.13 до 6.12.43 включительно (Linux)

Product types

Operating system, Application software

Platforms

Canonical Ltd. Ubuntu 22.04 LTS, Canonical Ltd. Ubuntu 24.04 LTS, Сообщество свободного программного обеспечения Debian GNU/Linux 13, Novell Inc. SUSE Linux Enterprise Server for SAP Applications 16.0, Novell Inc. Suse Linux Enterprise Server 16.0, Novell Inc. OpenSUSE Leap 16.0, Novell Inc. SUSE Linux Micro 6.2, Сообщество свободного программного обеспечения Linux от 6.13 до 6.16.3 включительно, Сообщество свободного программного обеспечения Linux от 5.13 до 6.12.43 включительно

Mitigations

В условиях отсутствия обновлений безопасности от производителя рекомендуется придерживаться "Рекомендаций по безопасной настройке операционных систем LINUX", изложенных в методическом документе ФСТЭК России, утверждённом 25 декабря 2022 года. Использование рекомендаций: Для Linux: https://lore.kernel.org/linux-cve-announce/2025091148-CVE-2025-39779-7d77@gregkh/ https://git.kernel.org/stable/c/3d61136945a7008fc90d013c3c67007ce0c96131 https://git.kernel.org/stable/c/bce7a5c77a1e7a759e227b7713dde18c52da4759 https://git.kernel.org/linus/b1511360c8ac882b0c52caa263620538e8d73220 https://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.44 https://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.16.4 Для Ubuntu: https://ubuntu.com/security/CVE-2025-39779 Для Debian GNU/Linux: https://security-tracker.debian.org/tracker/CVE-2025-39779 Для программных продуктов Novell Inc.: https://www.suse.com/security/cve/CVE-2025-39779.html

JSON

To clipboard

{
  "CVSS 2.0": "AV:L/AC:L/Au:S/C:N/I:N/A:C",
  "CVSS 3.0": "AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "CVSS 4.0": null,
  "remediation_\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": null,
  "remediation_\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435": null,
  "\u0412\u0435\u043d\u0434\u043e\u0440 \u041f\u041e": "Canonical Ltd., \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f, Novell Inc.",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "22.04 LTS (Ubuntu), 24.04 LTS (Ubuntu), 13 (Debian GNU/Linux), 16.0 (SUSE Linux Enterprise Server for SAP Applications), 16.0 (Suse Linux Enterprise Server), 16.0 (OpenSUSE Leap), 6.2 (SUSE Linux Micro), \u043e\u0442 6.13 \u0434\u043e 6.16.3 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 5.13 \u0434\u043e 6.12.43 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux)",
  "\u0412\u043e\u0437\u043c\u043e\u0436\u043d\u044b\u0435 \u043c\u0435\u0440\u044b \u043f\u043e \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044e": "\u0412 \u0443\u0441\u043b\u043e\u0432\u0438\u044f\u0445 \u043e\u0442\u0441\u0443\u0442\u0441\u0442\u0432\u0438\u044f \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0439 \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u043e\u0442 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u044f \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0443\u0435\u0442\u0441\u044f \u043f\u0440\u0438\u0434\u0435\u0440\u0436\u0438\u0432\u0430\u0442\u044c\u0441\u044f \"\u0420\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439 \u043f\u043e \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0439 \u043d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0435 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c LINUX\", \u0438\u0437\u043b\u043e\u0436\u0435\u043d\u043d\u044b\u0445 \u0432 \u043c\u0435\u0442\u043e\u0434\u0438\u0447\u0435\u0441\u043a\u043e\u043c \u0434\u043e\u043a\u0443\u043c\u0435\u043d\u0442\u0435 \u0424\u0421\u0422\u042d\u041a \u0420\u043e\u0441\u0441\u0438\u0438, \u0443\u0442\u0432\u0435\u0440\u0436\u0434\u0451\u043d\u043d\u043e\u043c 25 \u0434\u0435\u043a\u0430\u0431\u0440\u044f 2022 \u0433\u043e\u0434\u0430.\n\n\n\n\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439:\n\n\u0414\u043b\u044f Linux:\nhttps://lore.kernel.org/linux-cve-announce/2025091148-CVE-2025-39779-7d77@gregkh/\nhttps://git.kernel.org/stable/c/3d61136945a7008fc90d013c3c67007ce0c96131\nhttps://git.kernel.org/stable/c/bce7a5c77a1e7a759e227b7713dde18c52da4759\nhttps://git.kernel.org/linus/b1511360c8ac882b0c52caa263620538e8d73220\nhttps://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.44\nhttps://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.16.4\n\n\u0414\u043b\u044f Ubuntu:\nhttps://ubuntu.com/security/CVE-2025-39779\n\n\u0414\u043b\u044f Debian GNU/Linux:\nhttps://security-tracker.debian.org/tracker/CVE-2025-39779\n\n\u0414\u043b\u044f \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u044b\u0445 \u043f\u0440\u043e\u0434\u0443\u043a\u0442\u043e\u0432 Novell Inc.:\nhttps://www.suse.com/security/cve/CVE-2025-39779.html",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "31.07.2025",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "03.07.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "03.07.2026",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2026-09205",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u044b \u0434\u0440\u0443\u0433\u0438\u0445 \u0441\u0438\u0441\u0442\u0435\u043c \u043e\u043f\u0438\u0441\u0430\u043d\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "CVE-2025-39779",
  "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430",
  "\u041a\u043b\u0430\u0441\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043a\u043e\u0434\u0430",
  "\u041d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 \u041f\u041e": "Ubuntu, Debian GNU/Linux, SUSE Linux Enterprise Server for SAP Applications, Suse Linux Enterprise Server, OpenSUSE Leap, SUSE Linux Micro, Linux",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u041e\u0421 \u0438 \u0442\u0438\u043f \u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0439 \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u044b": "Canonical Ltd. Ubuntu 22.04 LTS , Canonical Ltd. Ubuntu 24.04 LTS , \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f Debian GNU/Linux 13 , Novell Inc. SUSE Linux Enterprise Server for SAP Applications 16.0 , Novell Inc. Suse Linux Enterprise Server 16.0 , Novell Inc. OpenSUSE Leap 16.0 , Novell Inc. SUSE Linux Micro 6.2 , \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f Linux \u043e\u0442 6.13 \u0434\u043e 6.16.3 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e , \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f Linux \u043e\u0442 5.13 \u0434\u043e 6.12.43 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e ",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0444\u0443\u043d\u043a\u0446\u0438\u0438 btrfs_subpage_set_writeback() \u043c\u043e\u0434\u0443\u043b\u044f fs/btrfs/subpage.c \u0444\u0430\u0439\u043b\u043e\u0432\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b btrfs \u044f\u0434\u0440\u0430 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b Linux, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u043e\u0442\u043a\u0430\u0437 \u0432 \u043e\u0431\u0441\u043b\u0443\u0436\u0438\u0432\u0430\u043d\u0438\u0438",
  "\u041d\u0430\u043b\u0438\u0447\u0438\u0435 \u044d\u043a\u0441\u043f\u043b\u043e\u0439\u0442\u0430": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "\u0414\u043e\u0441\u0442\u0443\u043f\u043d\u0430\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u044f assert() (CWE-617)",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0444\u0443\u043d\u043a\u0446\u0438\u0438 btrfs_subpage_set_writeback() \u043c\u043e\u0434\u0443\u043b\u044f fs/btrfs/subpage.c \u0444\u0430\u0439\u043b\u043e\u0432\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b btrfs \u044f\u0434\u0440\u0430 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b Linux \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u043d\u0435\u043a\u043e\u043d\u0442\u0440\u043e\u043b\u0438\u0440\u0443\u0435\u043c\u044b\u043c \u0434\u043e\u0441\u0442\u0438\u0436\u0438\u043c\u044b\u043c \u0443\u0442\u0432\u0435\u0440\u0436\u0434\u0435\u043d\u0438\u0435\u043c. \u042d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043c\u043e\u0436\u0435\u0442 \u043f\u043e\u0437\u0432\u043e\u043b\u0438\u0442\u044c \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u043e\u0442\u043a\u0430\u0437 \u0432 \u043e\u0431\u0441\u043b\u0443\u0436\u0438\u0432\u0430\u043d\u0438\u0438",
  "\u041f\u043e\u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u044f \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": null,
  "\u041f\u0440\u043e\u0447\u0430\u044f \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f": null,
  "\u0421\u0432\u044f\u0437\u044c \u0441 \u0438\u043d\u0446\u0438\u0434\u0435\u043d\u0442\u0430\u043c\u0438 \u0418\u0411": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u0421\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u0430",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044f": "\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438": "\u041c\u0430\u043d\u0438\u043f\u0443\u043b\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u0435 \u0441\u0442\u0440\u0443\u043a\u0442\u0443\u0440\u0430\u043c\u0438 \u0434\u0430\u043d\u043d\u044b\u0445",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://www.cve.org/CVERecord?id=CVE-2025-39779\nhttps://git.kernel.org/stable/c/3d61136945a7008fc90d013c3c67007ce0c96131\nhttps://git.kernel.org/stable/c/bce7a5c77a1e7a759e227b7713dde18c52da4759\nhttps://git.kernel.org/linus/b1511360c8ac882b0c52caa263620538e8d73220\nhttps://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.44\nhttps://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.16.4\nhttps://www.suse.com/security/cve/CVE-2025-39779.html\nhttps://security-tracker.debian.org/tracker/CVE-2025-39779\nhttps://ubuntu.com/security/CVE-2025-39779\nhttps://lore.kernel.org/linux-cve-announce/2025091148-CVE-2025-39779-7d77@gregkh/",
  "\u0421\u0442\u0430\u0442\u0443\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0434\u0442\u0432\u0435\u0440\u0436\u0434\u0435\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u0435\u043c",
  "\u0422\u0438\u043f \u041f\u041e": "\u041e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u0430\u044f \u0441\u0438\u0441\u0442\u0435\u043c\u0430, \u041f\u0440\u0438\u043a\u043b\u0430\u0434\u043d\u043e\u0435 \u041f\u041e \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u043e\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-617",
  "\u0423\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0421\u0440\u0435\u0434\u043d\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 4,6)\n\u0421\u0440\u0435\u0434\u043d\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 3.1 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 5,5)"
}

CVE-2025-39779 (GCVE-0-2025-39779)

Vulnerability from cvelistv5 – Published: 2025-09-11 16:56 – Updated: 2026-08-05 12:05

Title

btrfs: subpage: keep TOWRITE tag until folio is cleaned

Summary

In the Linux kernel, the following vulnerability has been resolved: btrfs: subpage: keep TOWRITE tag until folio is cleaned btrfs_subpage_set_writeback() calls folio_start_writeback() the first time a folio is written back, and it also clears the PAGECACHE_TAG_TOWRITE tag even if there are still dirty blocks in the folio. This can break ordering guarantees, such as those required by btrfs_wait_ordered_extents(). That ordering breakage leads to a real failure. For example, running generic/464 on a zoned setup will hit the following ASSERT. This happens because the broken ordering fails to flush existing dirty pages before the file size is truncated. assertion failed: !list_empty(&ordered->list) :: 0, in fs/btrfs/zoned.c:1899 ------------[ cut here ]------------ kernel BUG at fs/btrfs/zoned.c:1899! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 2 UID: 0 PID: 1906169 Comm: kworker/u130:2 Kdump: loaded Not tainted 6.16.0-rc6-BTRFS-ZNS+ #554 PREEMPT(voluntary) Hardware name: Supermicro Super Server/H12SSL-NT, BIOS 2.0 02/22/2021 Workqueue: btrfs-endio-write btrfs_work_helper [btrfs] RIP: 0010:btrfs_finish_ordered_zoned.cold+0x50/0x52 [btrfs] RSP: 0018:ffffc9002efdbd60 EFLAGS: 00010246 RAX: 000000000000004c RBX: ffff88811923c4e0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff827e38b1 RDI: 00000000ffffffff RBP: ffff88810005d000 R08: 00000000ffffdfff R09: ffffffff831051c8 R10: ffffffff83055220 R11: 0000000000000000 R12: ffff8881c2458c00 R13: ffff88811923c540 R14: ffff88811923c5e8 R15: ffff8881c1bd9680 FS: 0000000000000000(0000) GS:ffff88a04acd0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f907c7a918c CR3: 0000000004024000 CR4: 0000000000350ef0 Call Trace: <TASK> ? srso_return_thunk+0x5/0x5f btrfs_finish_ordered_io+0x4a/0x60 [btrfs] btrfs_work_helper+0xf9/0x490 [btrfs] process_one_work+0x204/0x590 ? srso_return_thunk+0x5/0x5f worker_thread+0x1d6/0x3d0 ? __pfx_worker_thread+0x10/0x10 kthread+0x118/0x230 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x205/0x260 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Consider process A calling writepages() with WB_SYNC_NONE. In zoned mode or for compressed writes, it locks several folios for delalloc and starts writing them out. Let's call the last locked folio folio X. Suppose the write range only partially covers folio X, leaving some pages dirty. Process A calls btrfs_subpage_set_writeback() when building a bio. This function call clears the TOWRITE tag of folio X, whose size = 8K and the block size = 4K. It is following state. 0 4K 8K |/////|/////| (flag: DIRTY, tag: DIRTY) <-----> Process A will write this range. Now suppose process B concurrently calls writepages() with WB_SYNC_ALL. It calls tag_pages_for_writeback() to tag dirty folios with PAGECACHE_TAG_TOWRITE. Since folio X is still dirty, it gets tagged. Then, B collects tagged folios using filemap_get_folios_tag() and must wait for folio X to be written before returning from writepages(). 0 4K 8K |/////|/////| (flag: DIRTY, tag: DIRTY|TOWRITE) However, between tagging and collecting, process A may call btrfs_subpage_set_writeback() and clear folio X's TOWRITE tag. 0 4K 8K | |/////| (flag: DIRTY|WRITEBACK, tag: DIRTY) As a result, process B won't see folio X in its batch, and returns without waiting for it. This breaks the WB_SYNC_ALL ordering requirement. Fix this by using btrfs_subpage_set_writeback_keepwrite(), which retains the TOWRITE tag. We now manually clear the tag only after the folio becomes clean, via the xas operation.

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/3d61136945a7008fc…
https://git.kernel.org/stable/c/bce7a5c77a1e7a759…
https://git.kernel.org/stable/c/b1511360c8ac882b0…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3470da3b7d87fde4b9729d4e29c2dc074cd59c10 , < 3d61136945a7008fc90d013c3c67007ce0c96131 (git) Affected: 3470da3b7d87fde4b9729d4e29c2dc074cd59c10 , < bce7a5c77a1e7a759e227b7713dde18c52da4759 (git) Affected: 3470da3b7d87fde4b9729d4e29c2dc074cd59c10 , < b1511360c8ac882b0c52caa263620538e8d73220 (git)
Linux	Linux	Affected: 5.13 Unaffected: 0 , < 5.13 (semver) Unaffected: 6.12.44 , ≤ 6.12.* (semver) Unaffected: 6.16.4 , ≤ 6.16.* (semver) Unaffected: 6.17 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/subpage.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3d61136945a7008fc90d013c3c67007ce0c96131",
              "status": "affected",
              "version": "3470da3b7d87fde4b9729d4e29c2dc074cd59c10",
              "versionType": "git"
            },
            {
              "lessThan": "bce7a5c77a1e7a759e227b7713dde18c52da4759",
              "status": "affected",
              "version": "3470da3b7d87fde4b9729d4e29c2dc074cd59c10",
              "versionType": "git"
            },
            {
              "lessThan": "b1511360c8ac882b0c52caa263620538e8d73220",
              "status": "affected",
              "version": "3470da3b7d87fde4b9729d4e29c2dc074cd59c10",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/subpage.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.13"
            },
            {
              "lessThan": "5.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.16.*",
              "status": "unaffected",
              "version": "6.16.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.17",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.44",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.16.4",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: subpage: keep TOWRITE tag until folio is cleaned\n\nbtrfs_subpage_set_writeback() calls folio_start_writeback() the first time\na folio is written back, and it also clears the PAGECACHE_TAG_TOWRITE tag\neven if there are still dirty blocks in the folio. This can break ordering\nguarantees, such as those required by btrfs_wait_ordered_extents().\n\nThat ordering breakage leads to a real failure. For example, running\ngeneric/464 on a zoned setup will hit the following ASSERT. This happens\nbecause the broken ordering fails to flush existing dirty pages before the\nfile size is truncated.\n\n  assertion failed: !list_empty(\u0026ordered-\u003elist) :: 0, in fs/btrfs/zoned.c:1899\n  ------------[ cut here ]------------\n  kernel BUG at fs/btrfs/zoned.c:1899!\n  Oops: invalid opcode: 0000 [#1] SMP NOPTI\n  CPU: 2 UID: 0 PID: 1906169 Comm: kworker/u130:2 Kdump: loaded Not tainted 6.16.0-rc6-BTRFS-ZNS+ #554 PREEMPT(voluntary)\n  Hardware name: Supermicro Super Server/H12SSL-NT, BIOS 2.0 02/22/2021\n  Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]\n  RIP: 0010:btrfs_finish_ordered_zoned.cold+0x50/0x52 [btrfs]\n  RSP: 0018:ffffc9002efdbd60 EFLAGS: 00010246\n  RAX: 000000000000004c RBX: ffff88811923c4e0 RCX: 0000000000000000\n  RDX: 0000000000000000 RSI: ffffffff827e38b1 RDI: 00000000ffffffff\n  RBP: ffff88810005d000 R08: 00000000ffffdfff R09: ffffffff831051c8\n  R10: ffffffff83055220 R11: 0000000000000000 R12: ffff8881c2458c00\n  R13: ffff88811923c540 R14: ffff88811923c5e8 R15: ffff8881c1bd9680\n  FS:  0000000000000000(0000) GS:ffff88a04acd0000(0000) knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: 00007f907c7a918c CR3: 0000000004024000 CR4: 0000000000350ef0\n  Call Trace:\n   \u003cTASK\u003e\n   ? srso_return_thunk+0x5/0x5f\n   btrfs_finish_ordered_io+0x4a/0x60 [btrfs]\n   btrfs_work_helper+0xf9/0x490 [btrfs]\n   process_one_work+0x204/0x590\n   ? srso_return_thunk+0x5/0x5f\n   worker_thread+0x1d6/0x3d0\n   ? __pfx_worker_thread+0x10/0x10\n   kthread+0x118/0x230\n   ? __pfx_kthread+0x10/0x10\n   ret_from_fork+0x205/0x260\n   ? __pfx_kthread+0x10/0x10\n   ret_from_fork_asm+0x1a/0x30\n   \u003c/TASK\u003e\n\nConsider process A calling writepages() with WB_SYNC_NONE. In zoned mode or\nfor compressed writes, it locks several folios for delalloc and starts\nwriting them out. Let\u0027s call the last locked folio folio X. Suppose the\nwrite range only partially covers folio X, leaving some pages dirty.\nProcess A calls btrfs_subpage_set_writeback() when building a bio. This\nfunction call clears the TOWRITE tag of folio X, whose size = 8K and\nthe block size = 4K. It is following state.\n\n   0     4K    8K\n   |/////|/////|  (flag: DIRTY, tag: DIRTY)\n   \u003c-----\u003e Process A will write this range.\n\nNow suppose process B concurrently calls writepages() with WB_SYNC_ALL. It\ncalls tag_pages_for_writeback() to tag dirty folios with\nPAGECACHE_TAG_TOWRITE. Since folio X is still dirty, it gets tagged. Then,\nB collects tagged folios using filemap_get_folios_tag() and must wait for\nfolio X to be written before returning from writepages().\n\n   0     4K    8K\n   |/////|/////|  (flag: DIRTY, tag: DIRTY|TOWRITE)\n\nHowever, between tagging and collecting, process A may call\nbtrfs_subpage_set_writeback() and clear folio X\u0027s TOWRITE tag.\n   0     4K    8K\n   |     |/////|  (flag: DIRTY|WRITEBACK, tag: DIRTY)\n\nAs a result, process B won\u0027t see folio X in its batch, and returns without\nwaiting for it. This breaks the WB_SYNC_ALL ordering requirement.\n\nFix this by using btrfs_subpage_set_writeback_keepwrite(), which retains\nthe TOWRITE tag. We now manually clear the tag only after the folio becomes\nclean, via the xas operation."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerable path is btrfs buffered-writeback reached only through local file syscalls (write/mmap dirtying, sync_file_range, fsync, ftruncate) on a mounted btrfs filesystem; there is no network or remote-peer input path into btrfs_subpage_set_writeback(). Exploitation requires the ability to run code on the machine.\nAC:L - The attacker drives both sides of the race himself \u2014 one thread issuing sync_file_range(SYNC_FILE_RANGE_WRITE) (WB_SYNC_NONE) over a partial range of a folio while another loops on fsync()/ftruncate() (WB_SYNC_ALL) \u2014 and can retry indefinitely until the window between tag_pages_for_writeback() and filemap_get_folios_tag() is hit. Subpage mode (sectorsize \u003c folio size) is a standard shipping deployment on 16K/64K-page arm64 and ppc64 kernels, not a rare debug option, and the compression/zoned delalloc behaviour that leaves partial dirty folios comes from ordinary mount options.\nPR:L - Only an ordinary unprivileged user with write access to any file on the btrfs filesystem (e.g. /home or /tmp) is needed \u2014 no capabilities, namespaces, or root, since dirtying pages and calling fsync/sync_file_range/ftruncate on one\u0027s own file is enough. The attacker owns the file involved in the race.\nUI:N - The attacker performs every step on a file it creates itself; no victim must mount a filesystem, open a file, or take any action. The already-mounted btrfs is normal system state.\nS:U - The broken writeback ordering, the empty-list dereference, and the resulting filesystem metadata damage are all handled by the same kernel security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - With CONFIG_BTRFS_ASSERT off, btrfs_finish_ordered_zoned() performs list_first_entry() on an empty list head, an out-of-bounds read of kernel memory preceding btrfs_ordered_extent::list, and that garbage value is written into ordered-\u003edisk_bytenr / em-\u003edisk_bytenr and persisted to the file extent item, remapping the attacker\u0027s file onto an arbitrary filesystem logical address whose contents (other files\u0027 data or freed blocks) can then be read back. The same ordering breakage lets truncate proceed without flushing, the exact condition btrfs\u0027s truncated_len machinery exists to prevent from exposing stale on-disk data.\nI:H - The corrupted logical address is committed into the extent map and the on-disk file extent item, an uncontrolled modification of filesystem metadata that can also misdirect extent-tree reference accounting onto blocks owned by other files. Independently, WB_SYNC_ALL writepages returning before the folio is written means fsync()/sync() acknowledge data that was never persisted, violating the durability and transaction-commit ordering guarantees btrfs_wait_ordered_extents() provides.\nA:H - The bug was reproduced as a hard kernel BUG \u2014 \"assertion failed: !list_empty(\u0026ordered-\u003elist)\" / \"Oops: invalid opcode\" in btrfs_finish_ordered_zoned() from a btrfs-endio-write worker \u2014 which panics the machine. Even without CONFIG_BTRFS_ASSERT, the fabricated btrfs_ordered_sum pointer and the possibly-NULL extent map in btrfs_rewrite_logical_zoned() readily oops the kernel."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:05:04.307Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/3d61136945a7008fc90d013c3c67007ce0c96131"
        },
        {
          "url": "https://git.kernel.org/stable/c/bce7a5c77a1e7a759e227b7713dde18c52da4759"
        },
        {
          "url": "https://git.kernel.org/stable/c/b1511360c8ac882b0c52caa263620538e8d73220"
        }
      ],
      "title": "btrfs: subpage: keep TOWRITE tag until folio is cleaned",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-39779",
    "datePublished": "2025-09-11T16:56:30.395Z",
    "dateReserved": "2025-04-16T07:20:57.130Z",
    "dateUpdated": "2026-08-05T12:05:04.307Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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BDU:2026-09205 (CVE-2025-39779)

CVE-2025-39779 (GCVE-0-2025-39779)

Tags

Sightings

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