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/arm64/tools/Makefile | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 arch/arm64/tools/Makefile (limited to 'arch/arm64/tools/Makefile') diff --git a/arch/arm64/tools/Makefile b/arch/arm64/tools/Makefile new file mode 100644 index 000000000..a94b3d9ca --- /dev/null +++ b/arch/arm64/tools/Makefile @@ -0,0 +1,34 @@ +# SPDX-License-Identifier: GPL-2.0 + +gen := arch/$(ARCH)/include/generated +kapi := $(gen)/asm + +kapisyshdr-y := cpucap-defs.h kernel-hwcap.h sysreg-defs.h + +kapi-hdrs-y := $(addprefix $(kapi)/, $(kapisyshdr-y)) + +targets += $(addprefix ../../../, $(kapi-hdrs-y)) + +PHONY += kapi + +all: $(syscall64) kapi + +kapi: $(kapi-hdrs-y) + +quiet_cmd_gen_cpucaps = GEN $@ + cmd_gen_cpucaps = mkdir -p $(dir $@); $(AWK) -f $(real-prereqs) > $@ + +quiet_cmd_gen_kernel_hwcap = GEN $@ + cmd_gen_kernel_hwcap = mkdir -p $(dir $@); /bin/sh -e $(real-prereqs) > $@ + +quiet_cmd_gen_sysreg = GEN $@ + cmd_gen_sysreg = mkdir -p $(dir $@); $(AWK) -f $(real-prereqs) > $@ + +$(kapi)/cpucap-defs.h: $(src)/gen-cpucaps.awk $(src)/cpucaps FORCE + $(call if_changed,gen_cpucaps) + +$(kapi)/kernel-hwcap.h: $(src)/gen-kernel-hwcaps.sh $(srctree)/arch/arm64/include/uapi/asm/hwcap.h FORCE + $(call if_changed,gen_kernel_hwcap) + +$(kapi)/sysreg-defs.h: $(src)/gen-sysreg.awk $(src)/sysreg FORCE + $(call if_changed,gen_sysreg) -- cgit v1.3.1