Null Pointer Dereference in Linux Kernel USB Gadget Function

CVE-2026-90019

What is CVE-2026-90019?

A vulnerability exists in the Linux kernel where the function usb_put_function_instance() incorrectly dereferences a null pointer. This occurs in the error path of uvc_alloc_inst(), where the fd variable of the fi struct is not allocated before it is accessed, leading to potential instability or crashes. A fix has been implemented to add a null check for fi->fd, ensuring this function exits gracefully if the fd is null, thus enhancing the overall stability and security of USB gadget functionalities.

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