The die_if_kernel function in arch/ia64/kernel/unaligned.c in Linux kernel 2.6.x before 2.6.15.6, possibly when compiled with certain versions of gcc, has the "noreturn" attribute set, which allows local users to cause a denial of service by causing user faults on Itanium systems.
The mincore function in the Linux kernel before 2.4.33.6 does not properly lock access to user space, which has unspecified impact and attack vectors, possibly related to a deadlock.
arch/powerpc/kvm/book3s_hv_rmhandlers.S in the Linux kernel through 4.7 on PowerPC platforms, when CONFIG_KVM_BOOK3S_64_HV is enabled, allows guest OS users to cause a denial of service (host OS infinite loop) by making a H_CEDE hypercall during the existence of a suspended transaction.