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 --- arch/riscv/boot/Makefile | 59 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 arch/riscv/boot/Makefile (limited to 'arch/riscv/boot/Makefile') diff --git a/arch/riscv/boot/Makefile b/arch/riscv/boot/Makefile new file mode 100644 index 000000000..fcfbe3f81 --- /dev/null +++ b/arch/riscv/boot/Makefile @@ -0,0 +1,59 @@ +# +# arch/riscv/boot/Makefile +# +# This file is included by the global makefile so that you can add your own +# architecture-specific flags and dependencies. +# +# This file is subject to the terms and conditions of the GNU General Public +# License. See the file "COPYING" in the main directory of this archive +# for more details. +# +# Copyright (C) 2018, Anup Patel. +# Author: Anup Patel +# +# Based on the ia64 and arm64 boot/Makefile. +# + +OBJCOPYFLAGS_Image :=-O binary -R .note -R .note.gnu.build-id -R .comment -S +OBJCOPYFLAGS_loader.bin :=-O binary +OBJCOPYFLAGS_xipImage :=-O binary -R .note -R .note.gnu.build-id -R .comment -S + +targets := Image Image.* loader loader.o loader.lds loader.bin xipImage + +$(obj)/Image: vmlinux FORCE + $(call if_changed,objcopy) + +$(obj)/Image.gz: $(obj)/Image FORCE + $(call if_changed,gzip) + +$(obj)/loader.o: $(src)/loader.S $(obj)/Image + +$(obj)/loader: $(obj)/loader.o $(obj)/Image $(obj)/loader.lds FORCE + $(Q)$(LD) -T $(obj)/loader.lds -o $@ $(obj)/loader.o + +$(obj)/Image.bz2: $(obj)/Image FORCE + $(call if_changed,bzip2) + +$(obj)/Image.lz4: $(obj)/Image FORCE + $(call if_changed,lz4) + +$(obj)/Image.lzma: $(obj)/Image FORCE + $(call if_changed,lzma) + +$(obj)/Image.lzo: $(obj)/Image FORCE + $(call if_changed,lzo) + +$(obj)/Image.zst: $(obj)/Image FORCE + $(call if_changed,zstd) + +$(obj)/Image.xz: $(obj)/Image FORCE + $(call if_changed,xzkern) + +$(obj)/loader.bin: $(obj)/loader FORCE + $(call if_changed,objcopy) + +EFI_ZBOOT_PAYLOAD := Image +EFI_ZBOOT_BFD_TARGET := elf$(BITS)-littleriscv +EFI_ZBOOT_MACH_TYPE := RISCV$(BITS) + +include $(srctree)/drivers/firmware/efi/libstub/Makefile.zboot -- cgit v1.3.1