From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- drivers/virt/Kconfig | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 drivers/virt/Kconfig (limited to 'drivers/virt/Kconfig') diff --git a/drivers/virt/Kconfig b/drivers/virt/Kconfig new file mode 100644 index 000000000..52eb7e4ba --- /dev/null +++ b/drivers/virt/Kconfig @@ -0,0 +1,52 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Virtualization support drivers +# + +menuconfig VIRT_DRIVERS + bool "Virtualization drivers" + help + Say Y here to get to see options for device drivers that support + virtualization environments. + + If you say N, all options in this submenu will be skipped and disabled. + +if VIRT_DRIVERS + +config VMGENID + tristate "Virtual Machine Generation ID driver" + default y + help + Say Y here to use the hypervisor-provided Virtual Machine Generation ID + to reseed the RNG when the VM is cloned. This is highly recommended if + you intend to do any rollback / cloning / snapshotting of VMs. + + Prefer Y to M so that this protection is activated very early. + +config FSL_HV_MANAGER + tristate "Freescale hypervisor management driver" + depends on FSL_SOC + select EPAPR_PARAVIRT + help + The Freescale hypervisor management driver provides several services + to drivers and applications related to the Freescale hypervisor: + + 1) An ioctl interface for querying and managing partitions. + + 2) A file interface to reading incoming doorbells. + + 3) An interrupt handler for shutting down the partition upon + receiving the shutdown doorbell from a manager partition. + + 4) A kernel interface for receiving callbacks when a managed + partition shuts down. + +source "drivers/virt/vboxguest/Kconfig" + +source "drivers/virt/nitro_enclaves/Kconfig" + +source "drivers/virt/acrn/Kconfig" + +endif + +source "drivers/virt/coco/Kconfig" -- cgit v1.3.1