Summary
In the Linux kernel, the following vulnerability has been resolved: HID: apple: validate feature...
In the Linux kernel, the following vulnerability has been resolved:
HID: apple: validate feature-report field count to prevent NULL pointer dereference
A malicious HID device with quirk APPLE_MAGIC_BACKLIGHT can trigger a NULL
pointer dereference whilst the power feature-report is toggled and sent to
the device in apple_magic_backlight_report_set(). The power feature-report
is expected to have two data fields, but if the descriptor declares one
field then accessing field[1] and dereferencing it in
apple_magic_backlight_report_set() becomes invalid
since field[1] will be NULL.
An example of a minimal descriptor which can cause the crash is something
like the following where the report with ID 3 (power report) only
references a single 1-byte field. When hid core parses the descriptor it
will encounter the final feature tag, allocate a hid_report (all members
of field[] will be zeroed out), create field structure and populate it,
increasing the maxfield to 1. The subsequent field[1] access and
dereference causes the crash.
Usage Page (Vendor Defined 0xFF00)
Usage (0x0F)
Collection (Application)
Report ID (1)
Usage (0x01)
Logical Minimum (0)
Logical Maximum (255)
Report Size (8)
Report Count (1)
Feature (Data,Var,Abs)
Usage (0x02)
Logical Maximum (32767)
Report Size (16)
Report Count (1)
Feature (Data,Var,Abs)
Report ID (3)
Usage (0x03)
Logical Minimum (0)
Logical Maximum (1)
Report Size (8)
Report Count (1)
Feature (Data,Var,Abs)
End Collection
Here we see the KASAN splat when the kernel dereferences the
NULL pointer and crashes:
[ 15.164723] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP KASAN NOPTI
[ 15.165691] KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
[ 15.165691] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.15.0 #31 PREEMPT(voluntary)
[ 15.165691] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 15.165691] RIP: 0010:apple_magic_backlight_report_set+0xbf/0x210
[ 15.165691] Call Trace:
[ 15.165691]
[ 15.165691] apple_probe+0x571/0xa20
[ 15.165691] hid_device_probe+0x2e2/0x6f0
[ 15.165691] really_probe+0x1ca/0x5c0
[ 15.165691] __driver_probe_device+0x24f/0x310
[ 15.165691] driver_probe_device+0x4a/0xd0
[ 15.165691] __device_attach_driver+0x169/0x220
[ 15.165691] bus_for_each_drv+0x118/0x1b0
[ 15.165691] __device_attach+0x1d5/0x380
[ 15.165691] device_initial_probe+0x12/0x20
[ 15.165691] bus_probe_device+0x13d/0x180
[ 15.165691] device_add+0xd87/0x1510
[...]
To fix this issue we should validate the number of fields that the
backlight and power reports have and if they do not have the required
number of fields then bail.
Impact
The application dereferences a null pointer, causing a crash. Typical impact: denial of service via crash.
CVE-2025-38557 has a CVSS score of 5.5 (Medium). 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.
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Frequently Asked Questions
- What is CVE-2025-38557? CVE-2025-38557 is a medium-severity null pointer dereference vulnerability. No fixed version is listed yet. The application dereferences a null pointer, causing a crash.
- How severe is CVE-2025-38557? CVE-2025-38557 has a CVSS score of 5.5 (Medium). 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-2025-38557? No fixed version is listed for CVE-2025-38557 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-38557 exploitable, and should I be worried? Whether CVE-2025-38557 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-2025-38557 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.