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 --- tools/testing/vma/Makefile | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 tools/testing/vma/Makefile (limited to 'tools/testing/vma/Makefile') diff --git a/tools/testing/vma/Makefile b/tools/testing/vma/Makefile new file mode 100644 index 000000000..e72b45ded --- /dev/null +++ b/tools/testing/vma/Makefile @@ -0,0 +1,21 @@ +# SPDX-License-Identifier: GPL-2.0-or-later + +.PHONY: default clean + +default: vma + +include ../shared/shared.mk + +OFILES = $(SHARED_OFILES) main.o shared.o maple-shim.o +TARGETS = vma + +# These can be varied to test different sizes. +CFLAGS += -DNUM_VMA_FLAG_BITS=128 -DNUM_MM_FLAG_BITS=128 + +main.o: main.c shared.c shared.h vma_internal.h tests/merge.c tests/mmap.c tests/vma.c ../../../mm/vma.c ../../../mm/vma_init.c ../../../mm/vma_exec.c ../../../mm/vma.h include/custom.h include/dup.h include/stubs.h + +vma: $(OFILES) + $(CC) $(CFLAGS) -o $@ $(OFILES) $(LDLIBS) + +clean: + $(RM) $(TARGETS) *.o radix-tree.c idr.c generated/map-shift.h generated/bit-length.h generated/autoconf.h -- cgit v1.3.1