CVE-2026-64363: Linux kernel · HID: appleir: fix UAF on pending key_up_timer in remove()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in b363d964ca829c1761c9f04188dfa28f90b0f2d4 : update Linux kernel when convenient.
Data as of 6 Nov 2026, 17:04 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in b363d964ca829c1761c9f04188dfa28f90b0f2d4, 3755f6e25776b8b12ddf062f9b573f05090e4034, 89ef67359672bf4cd6921524e39f61648fe38c0f +5
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: HID: appleir: fix UAF on pending key_up_timer in remove() appleir_remove() runs hid_hw_stop() before timer_delete_sync(). hid_hw_stop() synchronously unregisters the HID input device via hid_disconnect() -> hidinput_disconnect() -> input_unregister_device(), which drops the last reference and frees the underlying input_dev when no userspace handle holds it open. key_up_tick() reads appleir->input_dev and calls input_report_key() / input_sync() on it. The timer is armed from appleir_raw_event() with a HZ/8 (~125 ms) timeout on every keydown and key-repeat report. If a key was pressed shortly before the device is disconnected, the timer can fire after hid_hw_stop() has freed input_dev but before the teardown drains it. A simple reorder is not sufficient. Putting the timer drain first still leaves a window where a USB URB completion (raw_event) running during hid_hw_stop() can call mod_timer() and re-arm the timer, which then fires after hidinput_disconnect() has freed input_dev. The same URB-completion window also lets raw_event() reach key_up(), key_down() and battery_flat() directly, all of which dereference appleir->input_dev. Introduce a 'removing' flag on struct appleir, gated by the existing spinlock. appleir_remove() sets the flag under the lock and then shuts down the timer with timer_shutdown_sync(), which both drains any in-flight callback and permanently disables further mod_timer() calls. appleir_raw_event() and key_up_tick() bail out early if the flag is set, so no path can arm or run the timer, or dereference appleir->input_dev, after remove() has started tearing down. The keyrepeat and flatbattery branches of appleir_raw_event() previously called into the input layer without holding the spinlock; take it now so the flag check is well-defined. This incidentally closes a pre-existing read-side race on appleir->current_key in the keyrepeat branch. This bug is structurally a sibling of commit 4db2af929279 ("HID: appletb-kbd: fix UAF in inactivity-timer cleanup path") and has been present since the driver was introduced.
References
- git.kernel.org/stable/c/89ef67359672bf4cd6921524e39f61648fe38c0f (opens in a new tab)
- git.kernel.org/stable/c/3d30a0bb0e79621ae921b487835c56198adfafa3 (opens in a new tab)
- git.kernel.org/stable/c/37a52c61d4f78153c38ae1f7491dfcc8ac828dcf (opens in a new tab)
- git.kernel.org/stable/c/05e3decc55d1deca9410e0eb36466651fcbe57a5 (opens in a new tab)
- git.kernel.org/stable/c/3755f6e25776b8b12ddf062f9b573f05090e4034 (opens in a new tab)
- git.kernel.org/stable/c/b363d964ca829c1761c9f04188dfa28f90b0f2d4 (opens in a new tab)
- git.kernel.org/stable/c/6b0838e86da88b1d3bff86f19761ff25af73eaca (opens in a new tab)
- git.kernel.org/stable/c/75fe87e19d8aff81eb2c64d15d244ab8da4de945 (opens in a new tab)