CVE-2025-21813
published 2025-02-27CVE-2025-21813: In the Linux kernel, the following vulnerability has been resolved: timers/migration: Fix off-by-one root mis-connection Before attaching a new root to the old…
PriorityP421medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.19%
8.5th percentile
In the Linux kernel, the following vulnerability has been resolved:
timers/migration: Fix off-by-one root mis-connection
Before attaching a new root to the old root, the children counter of the
new root is checked to verify that only the upcoming CPU's top group have
been connected to it. However since the recently added commit b729cc1ec21a
("timers/migration: Fix another race between hotplug and idle entry/exit")
this check is not valid anymore because the old root is pre-accounted
as a child to the new root. Therefore after connecting the upcoming
CPU's top group to the new root, the children count to be expected must
be 2 and not 1 anymore.
This omission results in the old root to not be connected to the new
root. Then eventually the system may run with more than one top level,
which defeats the purpose of a single idle migrator.
Also the old root is pre-accounted but not connected upon the new root
creation. But it can be connected to the new root later on. Therefore
the old root may be accounted twice to the new root. The propagation of
such overcommit can end up creating a double final top-level root with a
groupmask incorrectly initialized. Although harmless given that the final
top level roots will never have a parent to walk up to, this oddity
opportunistically reported the core issue:
WARNING: CPU: 8 PID: 0 at kernel/time/timer_migration.c:543 tmigr_requires_handle_remote
CPU: 8 UID: 0 PID: 0 Comm: swapper/8
RIP: 0010:tmigr_requires_handle_remote
Call Trace:
? tmigr_requires_handle_remote
? hrtimer_run_queues
update_process_times
tick_periodic
tick_handle_periodic
__sysvec_apic_timer_interrupt
sysvec_apic_timer_interrupt
Fix the problem by taking the old root into account in the children count
of the new root so the connection is not omitted.
Also warn when more than one top level group exists to better detect
similar issues in the future.
Affected
12 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 6.12.15-1 (forky) | linux 6.12.15-1 (forky) |
| linux | linux | — | — |
| linux | linux | >= 12ead225b7996252a8bc1a49b03aad57c0794880 < c6dd70e5b465a2b77c7a7c3d868736d302e29aec | c6dd70e5b465a2b77c7a7c3d868736d302e29aec |
| linux | linux | >= 6.12.11 < 6.12.14 | 6.12.14 |
| linux | linux | >= b729cc1ec21a5899b7879ccfbe1786664928d597 < 6f449d8fa1808a7f9ee644866bbc079285dbefdd | 6f449d8fa1808a7f9ee644866bbc079285dbefdd |
| linux | linux | >= b729cc1ec21a5899b7879ccfbe1786664928d597 < 868c9037df626b3c245ee26a290a03ae1f9f58d3 | 868c9037df626b3c245ee26a290a03ae1f9f58d3 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 6.12.15-1 | 6.12.15-1 |
| linux | linux_kernel | >= 0 < 6.12.15-1 | 6.12.15-1 |
| linux | linux_kernel | >= 6.12.11 < 6.12.14 | 6.12.14 |
| linux | linux_kernel | >= 6.13.1 < 6.13.3 | 6.13.3 |
CVSS provenance
nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
vendor_ubuntu5.5MEDIUM
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OSV
linux-azure, linux-azure-6.11 vulnerabilities
osv·2025-05-07·CVSS 5.5
CVE-2025-21813 [MEDIUM] linux-azure, linux-azure-6.11 vulnerabilities
linux-azure, linux-azure-6.11 vulnerabilities
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Microsoft Azure Network Adapter (MANA) driver;
- Timer subsystem;
(CVE-2025-21813, CVE-2025-21953)
OSV
linux-realtime vulnerability
osv·2025-05-07·CVSS 5.5
CVE-2025-21813 [MEDIUM] linux-realtime vulnerability
linux-realtime vulnerability
A security issue was discovered in the Linux kernel.
An attacker could possibly use this to compromise the system.
This update corrects flaws in the following subsystems:
- Timer subsystem;
(CVE-2025-21813)
OSV
linux, linux-aws, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-lowlatency, linux-lowlatency-hwe-6.11, linux-oracle, linux-raspi vulnerability
osv·2025-05-06·CVSS 5.5
CVE-2025-21813 [MEDIUM] linux, linux-aws, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-lowlatency, linux-lowlatency-hwe-6.11, linux-oracle, linux-raspi vulnerability
linux, linux-aws, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-lowlatency, linux-lowlatency-hwe-6.11, linux-oracle, linux-raspi vulnerability
One security issue was discovered in the Linux kernel.
An attacker could possibly use this to compromise the system.
This update corrects flaws in the following subsystems:
- Timer subsystem;
(CVE-2025-21813)
OSV
linux-oem-6.11 vulnerabilities
osv·2025-05-06·CVSS 5.5
CVE-2025-21902 [MEDIUM] linux-oem-6.11 vulnerabilities
linux-oem-6.11 vulnerabilities
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- USB Type-C Connector System Software Interface driver;
- Timer subsystem;
(CVE-2025-21902, CVE-2025-21813)
GHSA
GHSA-xjrx-58mf-555f: In the Linux kernel, the following vulnerability has been resolved:
timers/migration: Fix off-by-one root mis-connection
Before attaching a new root
ghsa_unreviewed·2025-02-27
CVE-2025-21813 [MEDIUM] CWE-193 GHSA-xjrx-58mf-555f: In the Linux kernel, the following vulnerability has been resolved:
timers/migration: Fix off-by-one root mis-connection
Before attaching a new root
In the Linux kernel, the following vulnerability has been resolved:
timers/migration: Fix off-by-one root mis-connection
Before attaching a new root to the old root, the children counter of the
new root is checked to verify that only the upcoming CPU's top group have
been connected to it. However since the recently added commit b729cc1ec21a
("timers/migration: Fix another race between hotplug and idle entry/exit")
this check is not valid anymore because the old root is pre-accounted
as a child to the new root. Therefore after connecting the upcoming
CPU's top group to the new root, the children count to be expected must
be 2 and not 1 anymore.
This omission results in the old root to not be connected to the new
root. Then eventually the system may run with more than one top level,
which
OSV
CVE-2025-21813: In the Linux kernel, the following vulnerability has been resolved: timers/migration: Fix off-by-one root mis-connection Before attaching a new root t
osv·2025-02-27·CVSS 5.5
CVE-2025-21813 [MEDIUM] CVE-2025-21813: In the Linux kernel, the following vulnerability has been resolved: timers/migration: Fix off-by-one root mis-connection Before attaching a new root t
In the Linux kernel, the following vulnerability has been resolved: timers/migration: Fix off-by-one root mis-connection Before attaching a new root to the old root, the children counter of the new root is checked to verify that only the upcoming CPU's top group have been connected to it. However since the recently added commit b729cc1ec21a ("timers/migration: Fix another race between hotplug and idle entry/exit") this check is not valid anymore because the old root is pre-accounted as a child to the new root. Therefore after connecting the upcoming CPU's top group to the new root, the children count to be expected must be 2 and not 1 anymore. This omission results in the old root to not be connected to the new root. Then eventually the system may run with more than one top level, which de
Ubuntu
Linux kernel (Real-time) vulnerability
vendor_ubuntu·2025-05-07·CVSS 5.5
CVE-2025-21813 [MEDIUM] Linux kernel (Real-time) vulnerability
Title: Linux kernel (Real-time) vulnerability
Summary: The system could be made to crash under certain conditions.
A security issue was discovered in the Linux kernel.
An attacker could possibly use this to compromise the system.
This update corrects flaws in the following subsystems:
- Timer subsystem;
(CVE-2025-21813)
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard sy
Ubuntu
Linux kernel (Azure) vulnerabilities
vendor_ubuntu·2025-05-07·CVSS 5.5
CVE-2025-21813 [MEDIUM] Linux kernel (Azure) vulnerabilities
Title: Linux kernel (Azure) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Microsoft Azure Network Adapter (MANA) driver;
- Timer subsystem;
(CVE-2025-21813, CVE-2025-21953)
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, lin
Ubuntu
Linux kernel (OEM) vulnerabilities
vendor_ubuntu·2025-05-06·CVSS 5.5
CVE-2025-21813 [MEDIUM] Linux kernel (OEM) vulnerabilities
Title: Linux kernel (OEM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- USB Type-C Connector System Software Interface driver;
- Timer subsystem;
(CVE-2025-21902, CVE-2025-21813)
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generi
Ubuntu
Linux kernel vulnerability
vendor_ubuntu·2025-05-06·CVSS 5.5
CVE-2025-21813 [MEDIUM] Linux kernel vulnerability
Title: Linux kernel vulnerability
Summary: The system could be made to crash under certain conditions.
One security issue was discovered in the Linux kernel.
An attacker could possibly use this to compromise the system.
This update corrects flaws in the following subsystems:
- Timer subsystem;
(CVE-2025-21813)
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgra
Red Hat
kernel: timers/migration: Fix off-by-one root mis-connection
vendor_redhat·2025-02-27·CVSS 5.5
CVE-2025-21813 [MEDIUM] CWE-362 kernel: timers/migration: Fix off-by-one root mis-connection
kernel: timers/migration: Fix off-by-one root mis-connection
In the Linux kernel, the following vulnerability has been resolved:
timers/migration: Fix off-by-one root mis-connection
Before attaching a new root to the old root, the children counter of the
new root is checked to verify that only the upcoming CPU's top group have
been connected to it. However since the recently added commit b729cc1ec21a
("timers/migration: Fix another race between hotplug and idle entry/exit")
this check is not valid anymore because the old root is pre-accounted
as a child to the new root. Therefore after connecting the upcoming
CPU's top group to the new root, the children count to be expected must
be 2 and not 1 anymore.
This omission results in the old root to not be connected to the new
root. Then eventu
Debian
CVE-2025-21813: linux - In the Linux kernel, the following vulnerability has been resolved: timers/migr...
vendor_debian·2025·CVSS 5.5
CVE-2025-21813 [MEDIUM] CVE-2025-21813: linux - In the Linux kernel, the following vulnerability has been resolved: timers/migr...
In the Linux kernel, the following vulnerability has been resolved: timers/migration: Fix off-by-one root mis-connection Before attaching a new root to the old root, the children counter of the new root is checked to verify that only the upcoming CPU's top group have been connected to it. However since the recently added commit b729cc1ec21a ("timers/migration: Fix another race between hotplug and idle entry/exit") this check is not valid anymore because the old root is pre-accounted as a child to the new root. Therefore after connecting the upcoming CPU's top group to the new root, the children count to be expected must be 2 and not 1 anymore. This omission results in the old root to not be connected to the new root. Then eventually the system may run with more than one top level, which de
No detection rules found.
No public exploits indexed.
2025-02-27
Published