Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved: s390/mm: Fix VM_FAULT_HWPOISON handling in do_exception() There is no support for HWPOISON, MEMORY_FAILURE, or ARCH_HAS_COPY_MC on s390. Therefore we do not expect to see VM_FAULT_HWPOISON in do_exception(). However, since commit af19487f00f3 (“mm: make PTE_MARKER_SWAPIN_ERROR more general”), it is possible to see VM_FAULT_HWPOISON in combination with PTE_MARKER_POISONED, even on architectures that do not support HWPOISON otherwise. In this case, we will end up on the BUG() in do_exception(). Fix this by treating VM_FAULT_HWPOISON the same as VM_FAULT_SIGBUS, similar to x86 when MEMORY_FAILURE is not configured. Also print unexpected fault flags, for easier debugging. Note that VM_FAULT_HWPOISON_LARGE is not expected, because s390 cannot support swap entries on other levels than PTE level. A vulnerability was found in the Linux kernel in the function do_fault_error() where it is possible for a VM_FAULT_HWPOISON memory fault to appear in combination with PTE_MARKER_POISONED, even though the s390 architecture does not support HWPOISON. This can result in improper memory management and lead to crashes or kernel panics.Details
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Ubuntu 24.04 | Planned | — |