VulnerabilityPublished 6 Oct 2026Updated 19 Oct 2026

CVE-2026-98176: Linux kernel · drm/amdkfd: Avoid integer underflow with ffs in EOP ring size calc

Affects Linux kernelSource CVE Database V5

Not known to be exploited : upgrade to c883d0a132d430ef7ebb23fd94323be94d0fbdb8 or 82e1b8299c6da02ce02185c208d2fdf7572b5ea1 when convenient.

Data as of 26 Oct 2026, 12:55 UTC

Severity

Low

Rated Low by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in c883d0a132d430ef7ebb23fd94323be94d0fbdb8, 82e1b8299c6da02ce02185c208d2fdf7572b5ea1

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to c883d0a132d430ef7ebb23fd94323be94d0fbdb8 or 82e1b8299c6da02ce02185c208d2fdf7572b5ea1.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 14328aa58ce523a59996c5a82681c43ec048cc33, < c883d0a132d430ef7ebb23fd94323be94d0fbdb8	Fixed in c883d0a132d430ef7ebb23fd94323be94d0fbdb8
LinuxLinux	Affected ≥ 14328aa58ce523a59996c5a82681c43ec048cc33, < 82e1b8299c6da02ce02185c208d2fdf7572b5ea1	Fixed in 82e1b8299c6da02ce02185c208d2fdf7572b5ea1
LinuxLinux	Affected =5.3	Fixed in–

AI-suggested

This vulnerability has been fixed in the Linux kernel by commits c883d0a132d430ef7ebb23fd94323be94d0fbdb8 and 82e1b8299c6da02ce02185c208d2fdf7572b5ea1. Users and administrators should update to a Linux kernel version that includes these commits or later to remediate the issue.

Description

A vulnerability in the Linux kernel's drm/amdkfd component involved an integer underflow in the calculation of the EOP ring size. The issue arose from using the ffs function on the ring buffer size, which could theoretically return 0 or 1, causing an underflow in the calculation. This was addressed by adjusting the calculation to avoid the underflow condition. The vulnerability affects Linux kernel version 5.3 and has been fixed in specific commits.

Impact

The vulnerability could cause an integer underflow in the kernel's drm/amdkfd driver during EOP ring size calculation. While the practical impact is limited by the minimum ring buffer size, the flaw could potentially lead to incorrect calculations affecting kernel stability or behavior. No known exploits in the wild have been reported.

Summary

The Linux kernel's drm/amdkfd driver had a vulnerability due to an integer underflow in the calculation of the EOP ring size. The low 6 bits of cp_hqd_eop_control store the base-2 logarithm of the EOP ring size, originally calculated as ffs(q->eop_ring_buffer_size / sizeof(unsigned int)) - 2. Since ffs can return 0 or 1, this could cause an underflow, although practically the ring buffer size is not less than 4096. The fix changes the calculation to ffs(q->eop_ring_buffer_size / sizeof(unsigned int) / 4), leveraging logarithm properties to avoid underflow. The fix was applied in commits c883d0a132d430ef7ebb23fd94323be94d0fbdb8 and 82e1b8299c6da02ce02185c208d2fdf7572b5ea1.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 12:27 UTC

Technical details

References

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