Summary
In the Linux kernel, the following vulnerability has been resolved: HID: appletb-kbd: fix slab...
In the Linux kernel, the following vulnerability has been resolved:
HID: appletb-kbd: fix slab use-after-free bug in appletb_kbd_probe
In probe appletb_kbd_probe() a "struct appletb_kbd *kbd" is allocated
via devm_kzalloc() to store touch bar keyboard related data.
Later on if backlight_device_get_by_name() finds a backlight device
with name "appletb_backlight" a timer (kbd->inactivity_timer) is setup
with appletb_inactivity_timer() and the timer is armed to run after
appletb_tb_dim_timeout (60) seconds.
A use-after-free is triggered when failure occurs after the timer is
armed. This ultimately means probe failure occurs and as a result the
"struct appletb_kbd *kbd" which is device managed memory is freed.
After 60 seconds the timer will have expired and __run_timers will
attempt to access the timer (kbd->inactivity_timer) however the kdb
structure has been freed causing a use-after free.
[ 71.636938] ==================================================================
[ 71.637915] BUG: KASAN: slab-use-after-free in __run_timers+0x7ad/0x890
[ 71.637915] Write of size 8 at addr ffff8881178c5958 by task swapper/1/0
[ 71.637915]
[ 71.637915] CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc2-00318-g739a6c93cc75-dirty #12 PREEMPT(voluntary)
[ 71.637915] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 71.637915] Call Trace:
[ 71.637915]
[ 71.637915] dump_stack_lvl+0x53/0x70
[ 71.637915] print_report+0xce/0x670
[ 71.637915] ? __run_timers+0x7ad/0x890
[ 71.637915] kasan_report+0xce/0x100
[ 71.637915] ? __run_timers+0x7ad/0x890
[ 71.637915] __run_timers+0x7ad/0x890
[ 71.637915] ? __pfx___run_timers+0x10/0x10
[ 71.637915] ? update_process_times+0xfc/0x190
[ 71.637915] ? __pfx_update_process_times+0x10/0x10
[ 71.637915] ? _raw_spin_lock_irq+0x80/0xe0
[ 71.637915] ? _raw_spin_lock_irq+0x80/0xe0
[ 71.637915] ? __pfx__raw_spin_lock_irq+0x10/0x10
[ 71.637915] run_timer_softirq+0x141/0x240
[ 71.637915] ? __pfx_run_timer_softirq+0x10/0x10
[ 71.637915] ? __pfx___hrtimer_run_queues+0x10/0x10
[ 71.637915] ? kvm_clock_get_cycles+0x18/0x30
[ 71.637915] ? ktime_get+0x60/0x140
[ 71.637915] handle_softirqs+0x1b8/0x5c0
[ 71.637915] ? __pfx_handle_softirqs+0x10/0x10
[ 71.637915] irq_exit_rcu+0xaf/0xe0
[ 71.637915] sysvec_apic_timer_interrupt+0x6c/0x80
[ 71.637915]
[ 71.637915]
[ 71.637915] Allocated by task 39:
[ 71.637915] kasan_save_stack+0x33/0x60
[ 71.637915] kasan_save_track+0x14/0x30
[ 71.637915] __kasan_kmalloc+0x8f/0xa0
[ 71.637915] __kmalloc_node_track_caller_noprof+0x195/0x420
[ 71.637915] devm_kmalloc+0x74/0x1e0
[ 71.637915] appletb_kbd_probe+0x37/0x3c0
[ 71.637915] hid_device_probe+0x2d1/0x680
[ 71.637915] really_probe+0x1c3/0x690
[ 71.637915] __driver_probe_device+0x247/0x300
[ 71.637915] driver_probe_device+0x49/0x210
[...]
[ 71.637915]
[ 71.637915] Freed by task 39:
[ 71.637915] kasan_save_stack+0x33/0x60
[ 71.637915] kasan_save_track+0x14/0x30
[ 71.637915] kasan_save_free_info+0x3b/0x60
[ 71.637915] __kasan_slab_free+0x37/0x50
[ 71.637915] kfree+0xcf/0x360
[ 71.637915] devres_release_group+0x1f8/0x3c0
[ 71.637915] hid_device_probe+0x315/0x680
[ 71.637915] really_probe+0x1c3/0x690
[ 71.637915] __driver_probe_device+0x247/0x300
[ 71.637915] driver_probe_device+0x49/0x210
[...]
The root cause of the issue is that the timer is not disarmed
on failure paths leading to it remaining active and accessing
freed memory. To fix this call timer_delete_sync() to deactivate
the timer.
Another small issue is that timer_delete_sync is called
unconditionally in appletb_kbd_remove(), fix this by checking
for a valid kbd->backlight_dev before calling timer_delete_sync.
Impact
Memory is accessed after it has been freed, leading to undefined behavior in native code. Typical impact: memory corruption, crash, or potential code execution.
CVE-2025-38378 has a CVSS score of 7.8 (High). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Frequently Asked Questions
- What is CVE-2025-38378? CVE-2025-38378 is a high-severity use after free vulnerability. No fixed version is listed yet. Memory is accessed after it has been freed, leading to undefined behavior in native code.
- How severe is CVE-2025-38378? CVE-2025-38378 has a CVSS score of 7.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Is there a fix for CVE-2025-38378? No fixed version is listed for CVE-2025-38378 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-38378 exploitable, and should I be worried? Whether CVE-2025-38378 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-38378 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.