A flaw was found in the Linux kernel. A use-after-free may be triggered in asus_kbd_backlight_set when plugging/disconnecting in a malicious USB device, which advertises itself as an Asus device. Similarly to the previous known CVE-2023-25012, but in asus devices, the work_struct may be scheduled by the LED controller while the device is disconnecting, triggering a use-after-free on the struct asus_kbd_leds *led structure. A malicious USB device may exploit the issue to cause memory corruption with controlled data.
Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Linux_kernel | Linux | * | 6.3 (excluding) |
The use of previously-freed memory can have any number of adverse consequences, ranging from the corruption of valid data to the execution of arbitrary code, depending on the instantiation and timing of the flaw. The simplest way data corruption may occur involves the system’s reuse of the freed memory. Use-after-free errors have two common and sometimes overlapping causes:
In this scenario, the memory in question is allocated to another pointer validly at some point after it has been freed. The original pointer to the freed memory is used again and points to somewhere within the new allocation. As the data is changed, it corrupts the validly used memory; this induces undefined behavior in the process. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.