kernel: x86-64: seccomp: 32/64 syscall hole

The securecomputing function in kernel/seccomp.c in the seccomp subsystem in the Linux kernel 2.6.28.7 and earlier on the x8664 platform, when CONFIGSECCOMP is enabled, does not properly handle 1 a 32-bit process making a 64-bit syscall or 2 a 64-bit process making a 32-bit syscall, which allows...