In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_mass_storage: fix null pointer dereference in fsg_common

In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: f_mass_storage: fix null pointer dereference in fsg_common_set_num_buffers()

Previously fsg_num_buffers_validate() was removed as it was not
necessary due to Kconfig setting the limits for n from 2 to 256 with
default as 2. However, setting the page content in such a way that
kstrtou8() reflects n value as either 0 or 1 bypasses these
restrictions leading to a null pointer dereference if n is 0. Fix
this by adding a check for n < 2 and returning -EINVAL if n is
either 0 or 1 consistent with Kconfig logic.