On Wed, Jan 22, 2025 at 07:39:31PM +0100, Thomas Weißschuh wrote: > The ioctl and sysfs handlers unconditionally call the ->enable callback. > Not all drivers implement that callback, leading to NULL dereferences. > Example of affected drivers: ptp_s390.c, ptp_vclock.c and ptp_mock.c. > + if (!ptp->info->enable) > + ptp->info->enable = ptp_enable; Is it possible that a driver has defined info as a const, and placed it into read only memory? It is generally good practice to make structures of ops read only to prevent some forms of attack. Andrew