VulnerabilityPublished 28 Oct 2026

CVE-2026-99135: Linux kernel · dm-integrity: fix infinite loop on discard with large tag size

Source GCVE Database

Authoritative record:CVE-2026-99135

Not known to be exploited · fixed in fc512700f1413fed652dac22fa1c4e837210b9c0 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 14:13 UTC

Severity

Medium

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

Patch: Available – fixed in fc512700f1413fed652dac22fa1c4e837210b9c0, 251b44b424920df9204e88a81fb3f78fa48ddd99, 18d80c77b4c7dd20699e81cedfbbff4e9d198f28

Exploitation evidence

Disclosed: evidence found.
CVE published 28 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.

ghsa-9xjj-2vj5-5vwq

What to do

Upgrade Linux kernel to fc512700f1413fed652dac22fa1c4e837210b9c0, 251b44b424920df9204e88a81fb3f78fa48ddd99 or 18d80c77b4c7dd20699e81cedfbbff4e9d198f28.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 84597a44a9d86ac949900441cea7da0af0f2f473, < fc512700f1413fed652dac22fa1c4e837210b9c0	Fixed in fc512700f1413fed652dac22fa1c4e837210b9c0
LinuxLinux	Affected ≥ 84597a44a9d86ac949900441cea7da0af0f2f473, < 251b44b424920df9204e88a81fb3f78fa48ddd99	Fixed in 251b44b424920df9204e88a81fb3f78fa48ddd99
LinuxLinux	Affected ≥ 84597a44a9d86ac949900441cea7da0af0f2f473, < 18d80c77b4c7dd20699e81cedfbbff4e9d198f28	Fixed in 18d80c77b4c7dd20699e81cedfbbff4e9d198f28
LinuxLinux	Affected =5.7	Fixed in–

AI-suggested

A fix has been implemented that changes the calculation of max_size to use the size of the on-stack array, ensuring the loop terminates properly. Users should apply the official kernel update containing this fix once available. No other mitigation or workaround is indicated.

Description

A vulnerability in the Linux kernel's dm-integrity module could cause an infinite loop during discard operations when using a large tag size. This occurs because the loop controlling the discard process never decrements its counter if the tag size exceeds a certain buffer size, leading to non-termination.

Impact

The vulnerability can cause the dm-integrity discard operation to enter an infinite loop, potentially leading to a denial of service condition by hanging the kernel thread handling the discard. There is no indication of code execution or data corruption from the provided information.

Summary

The Linux kernel's dm-integrity module had a flaw where, during discard operations, it fills a buffer with DISCARD_FILLER and writes over tags in blocks. If memory allocation (kmalloc) fails, the buffer falls back to an on-stack array with a fixed size (HASH_MAX_DIGESTSIZE). When the tag size is larger than this fallback buffer size, the calculation of max_blocks results in zero, causing the loop controlling the discard operation to never decrement and thus never terminate. The fix involved using the actual size of the on-stack array (MAX_TAG_SIZE) to ensure max_blocks is at least one, preventing the infinite loop.

References

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