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/memblock/scripts/Makefile.include | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 tools/testing/memblock/scripts/Makefile.include (limited to 'tools/testing/memblock/scripts') diff --git a/tools/testing/memblock/scripts/Makefile.include b/tools/testing/memblock/scripts/Makefile.include new file mode 100644 index 000000000..998281723 --- /dev/null +++ b/tools/testing/memblock/scripts/Makefile.include @@ -0,0 +1,19 @@ +# SPDX-License-Identifier: GPL-2.0 +# Definitions for user-provided arguments + +# Simulate CONFIG_NUMA=y +ifeq ($(NUMA), 1) + CFLAGS += -D CONFIG_NUMA -D CONFIG_NODES_SHIFT=4 +endif + +# Use 32 bit physical addresses. +# Remember to install 32-bit version of dependencies. +ifeq ($(32BIT_PHYS_ADDR_T), 1) + CFLAGS += -m32 -U CONFIG_PHYS_ADDR_T_64BIT + LDFLAGS += -m32 +endif + +# Enable memblock_dbg() messages +ifeq ($(MEMBLOCK_DEBUG), 1) + CFLAGS += -D MEMBLOCK_DEBUG +endif -- cgit v1.3.1