CVE-2026-64574
CVE-2026-64574 is a security vulnerability in Kernel. O3 Security confirms whether CVE-2026-64574 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
wifi: mac80211: tear down new links on vif update error path
Real-World Exposure
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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
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐧Linux | Kernel | ≥ 6.4.0&&< 6.6.148 | 6.6.148 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Kernel to 6.6.148 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-64574 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-64574 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-64574. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-64574 in your dependencies?
O3 detects CVE-2026-64574 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.