Race Condition in Linux Kernel Affecting USB Gadget Functionality

CVE-2025-40315

What is CVE-2025-40315?

A race condition exists in the USB gadget subsystem of the Linux kernel that arises when the ffs_func_eps_enable() function is executed simultaneously with ffs_data_reset(). This situation can lead to a null pointer dereference due to the premature setting of the ffs->epfiles pointer to NULL during the execution of ffs_data_clear() in ffs_data_reset(). The improper handling of this pointer in the context of enabled endpoints can cause significant instability in USB operations. The fix requires enhanced NULL pointer handling within the ffs_func_eps_enable() function to mitigate the risks associated with concurrent access to these resources.

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