CVE-2026-93219 - Vulnerability Details

- clocksource/drivers/timer-sun4i: Advertise a real minimum delta

Description

In the Linux kernel, the following vulnerability has been resolved:

clocksource/drivers/timer-sun4i: Advertise a real minimum delta

sun4i_clkevt_next_event() compensates for the timer stop/start
synchronization delay by programming evt - TIMER_SYNC_TICKS into the
hardware interval register. The clockevent device currently advertises
TIMER_SYNC_TICKS as min_delta_ticks, so the clockevents core is allowed
to call set_next_event() with evt == TIMER_SYNC_TICKS.

That programs a zero-tick interval. With oneshot/highres/nohz timer
operation this can leave the next event stuck, which was observed as a
boot hang on Allwinner D1 after the clockevents core started reusing
forced minimum-delta events.

Advertise one extra tick instead, so the smallest event accepted by the
core still programs at least one hardware tick after the synchronization
compensation.

Published: 2026-09-24

Score: n/a

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

The kernel timer driver incorrectly advertises a minimum tick value that allows a zero‑tick interval. When the clockevents core schedules a next event at this value, the hardware timer receives a zero‑tick request, causing the event to never fire. On configurations using oneshot, high‑resolution, or no‑hz timers, this results in the system becoming stuck during boot, effectively halting the machine until a reset.

Affected Systems

All Linux kernel builds that include the sun4i timer driver before the published fix are affected. The exact range of affected kernel releases is not specified in the available data; any kernel that has not yet been updated to include the min_delta_ticks correction is vulnerable.

Risk and Exploitability

The vulnerability is not documented in CISA's KEV catalog and no EPSS score is available, but its impact is significant: a local attacker with ability to influence the timer scheduling or a normal boot process can trigger a shutdown of the system. The issue stems from improper input validation and resource management in the timer driver, which elevates the risk of exploitation to local privilege or pre‑boot scenarios.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`12e1480bcb4920c1b02b3793cb48756497919a60`	affected	< 0cc4b14d7401d50e53a01f1554147ee075ee6943
`12e1480bcb4920c1b02b3793cb48756497919a60`	affected	< 53a3bc024b8e5d284468cce84957cded5f859f98
`12e1480bcb4920c1b02b3793cb48756497919a60`	affected	< 753a220084dfc4d737f2ab9eaddc9a01a397edd7
`12e1480bcb4920c1b02b3793cb48756497919a60`	affected	< ebba4d0aeba0e8eb3a9676380fc2652de8ab1c44
`12e1480bcb4920c1b02b3793cb48756497919a60`	affected	< 151eb52f8712017c8f7b00bb2305e8916cb9e3dc
`12e1480bcb4920c1b02b3793cb48756497919a60`	affected	< bf38be01d43c4e4ca903aff7236d8486a950a252
`12e1480bcb4920c1b02b3793cb48756497919a60`	affected	< f0efafcdf6eec1f3361bfd8c811420198f55c8bb
`12e1480bcb4920c1b02b3793cb48756497919a60`	affected	< d21808328225ab8cee46885bf9a0dffcefbe630e

Linux

affected

Version	Status	Constraints
`3.13`	affected	—
`0`	unaffected	< 3.13
`5.10.270`	unaffected	≤ 5.10.*
`5.15.221`	unaffected	≤ 5.15.*
`6.1.188`	unaffected	≤ 6.1.*
`6.6.157`	unaffected	≤ 6.6.*
`6.12.109`	unaffected	≤ 6.12.*
`6.18.50`	unaffected	≤ 6.18.*
`7.2.4`	unaffected	≤ 7.2.*
`7.3-rc1`	unaffected	≤ *

No data.

Vendor Product Confidence Versions

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`[12e1480bcb4920c1b02b3793cb48756497919a60,0cc4b14d7401d50e53a01f1554147ee075ee6943)`	affected	code_commit	—
`[12e1480bcb4920c1b02b3793cb48756497919a60,53a3bc024b8e5d284468cce84957cded5f859f98)`	affected	code_commit	—
`[12e1480bcb4920c1b02b3793cb48756497919a60,753a220084dfc4d737f2ab9eaddc9a01a397edd7)`	affected	code_commit	—
`[12e1480bcb4920c1b02b3793cb48756497919a60,ebba4d0aeba0e8eb3a9676380fc2652de8ab1c44)`	affected	code_commit	—
`[12e1480bcb4920c1b02b3793cb48756497919a60,151eb52f8712017c8f7b00bb2305e8916cb9e3dc)`	affected	code_commit	—
`[12e1480bcb4920c1b02b3793cb48756497919a60,bf38be01d43c4e4ca903aff7236d8486a950a252)`	affected	code_commit	—
`[12e1480bcb4920c1b02b3793cb48756497919a60,f0efafcdf6eec1f3361bfd8c811420198f55c8bb)`	affected	code_commit	—
`[12e1480bcb4920c1b02b3793cb48756497919a60,d21808328225ab8cee46885bf9a0dffcefbe630e)`	affected	code_commit	—

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`3.13`	affected	semver	—
`[0,3.13)`	unaffected	semver	—
`[5.10.270,5.11.0)`	unaffected	semver	—
`[5.15.221,5.16.0)`	unaffected	semver	—
`[6.1.188,6.2.0)`	unaffected	semver	—
`[6.6.157,6.7.0)`	unaffected	semver	—
`[6.12.109,6.13.0)`	unaffected	semver	—
`[6.18.50,6.19.0)`	unaffected	semver	—
`[7.2.4,7.3.0)`	unaffected	semver	—
`[7.3-rc1,*]`	unaffected	semver	—

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Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Apply a Linux kernel update that incorporates the patch changing the advertised minimum delta for the sun4i timer driver.
If a kernel upgrade cannot be applied immediately, reconfigure the system to avoid using the sun4i timer as its primary clocksource, for example by selecting an alternative clocksource via kernel parameters or the clocksource interface.
After applying the fix or reconfiguration, reboot the system and verify that the kernel stops reporting the zero‑tick interval and that the system boots normally.

Generated by OpenCVE AI on September 25, 2026 at 10:59 UTC.

Tracking

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Advisories

Source	ID	Title
Debian DLA	DLA-4817-1	linux-6.12 security update
Debian DSA	DSA-6528-1	linux security update

No CVSS v4.0

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00176.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/0cc4b14d7401d50e53a01f1554147ee075ee6943
https://git.kernel.org/stable/c/151eb52f8712017c8f7b00bb2305e8916cb9e3dc
https://git.kernel.org/stable/c/53a3bc024b8e5d284468cce84957cded5f859f98
https://git.kernel.org/stable/c/753a220084dfc4d737f2ab9eaddc9a01a397edd7
https://git.kernel.org/stable/c/bf38be01d43c4e4ca903aff7236d8486a950a252
https://git.kernel.org/stable/c/d21808328225ab8cee46885bf9a0dffcefbe630e
https://git.kernel.org/stable/c/ebba4d0aeba0e8eb3a9676380fc2652de8ab1c44
https://git.kernel.org/stable/c/f0efafcdf6eec1f3361bfd8c811420198f55c8bb

History

Fri, 25 Sep 2026 11:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-20 CWE-399

Thu, 24 Sep 2026 15:30:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: clocksource/drivers/timer-sun4i: Advertise a real minimum delta sun4i_clkevt_next_event() compensates for the timer stop/start synchronization delay by programming evt - TIMER_SYNC_TICKS into the hardware interval register. The clockevent device currently advertises TIMER_SYNC_TICKS as min_delta_ticks, so the clockevents core is allowed to call set_next_event() with evt == TIMER_SYNC_TICKS. That programs a zero-tick interval. With oneshot/highres/nohz timer operation this can leave the next event stuck, which was observed as a boot hang on Allwinner D1 after the clockevents core started reusing forced minimum-delta events. Advertise one extra tick instead, so the smallest event accepted by the core still programs at least one hardware tick after the synchronization compensation.
Title		clocksource/drivers/timer-sun4i: Advertise a real minimum delta
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/0cc4b14d7401d50e53a01f1554147ee075ee6943 https://git.kernel.org/stable/c/151eb52f8712017c8f7b00bb2305e8916cb9e3dc https://git.kernel.org/stable/c/53a3bc024b8e5d284468cce84957cded5f859f98 https://git.kernel.org/stable/c/753a220084dfc4d737f2ab9eaddc9a01a397edd7 https://git.kernel.org/stable/c/bf38be01d43c4e4ca903aff7236d8486a950a252 https://git.kernel.org/stable/c/d21808328225ab8cee46885bf9a0dffcefbe630e https://git.kernel.org/stable/c/ebba4d0aeba0e8eb3a9676380fc2652de8ab1c44 https://git.kernel.org/stable/c/f0efafcdf6eec1f3361bfd8c811420198f55c8bb

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-09-24T15:10:42.900Z

Updated: 2026-09-24T15:10:42.900Z

Reserved: 2026-09-17T16:02:15.094Z

Link: CVE-2026-93219

Vulnrichment

No data.

NVD

Status : Received

Published: 2026-09-24T16:17:17.030

Modified: 2026-09-24T16:17:17.030

Link: CVE-2026-93219

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-09-25T11:00:12Z

Weaknesses

CWE-20
Improper Input Validation
CWE-399

Impact

Affected Systems

Risk and Exploitability

Tracking

Subscriptions

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