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/Makefile | 55 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 tools/testing/memblock/Makefile (limited to 'tools/testing/memblock/Makefile') diff --git a/tools/testing/memblock/Makefile b/tools/testing/memblock/Makefile new file mode 100644 index 000000000..d80982ccd --- /dev/null +++ b/tools/testing/memblock/Makefile @@ -0,0 +1,55 @@ +# SPDX-License-Identifier: GPL-2.0 + +# Memblock simulator requires AddressSanitizer (libasan) and liburcu development +# packages installed +CFLAGS += -I. -I../../include -Wall -O2 -fsanitize=address \ + -fsanitize=undefined -D CONFIG_PHYS_ADDR_T_64BIT +LDFLAGS += -fsanitize=address -fsanitize=undefined +TARGETS = main +TEST_OFILES = tests/alloc_nid_api.o tests/alloc_helpers_api.o tests/alloc_api.o \ + tests/basic_api.o tests/common.o tests/alloc_exact_nid_api.o +DEP_OFILES = memblock.o lib/slab.o mmzone.o slab.o cmdline.o +OFILES = main.o $(DEP_OFILES) $(TEST_OFILES) +EXTR_SRC = ../../../mm/memblock.c + +ifeq ($(BUILD), 32) + CFLAGS += -m32 + LDFLAGS += -m32 +endif + +# Process user parameters +include scripts/Makefile.include + +main: $(OFILES) + +$(OFILES): include + +include: ../../../include/linux/memblock.h ../../include/linux/*.h \ + ../../include/asm/*.h + + @mkdir -p linux + test -L linux/memblock.h || ln -s ../../../../include/linux/memblock.h linux/memblock.h + test -L asm/asm.h || ln -s ../../../arch/x86/include/asm/asm.h asm/asm.h + test -L asm/cmpxchg.h || ln -s ../../../arch/x86/include/asm/cmpxchg.h asm/cmpxchg.h + +memblock.c: $(EXTR_SRC) + test -L memblock.c || ln -s $(EXTR_SRC) memblock.c + +clean: + $(RM) $(TARGETS) $(OFILES) linux/memblock.h memblock.c asm/asm.h asm/cmpxchg.h + +help: + @echo 'Memblock simulator' + @echo '' + @echo 'Available targets:' + @echo ' main - Build the memblock simulator' + @echo ' clean - Remove generated files and symlinks in the directory' + @echo '' + @echo 'Configuration:' + @echo ' make MEMBLOCK_DEBUG=1 - enable memblock_dbg() messages' + @echo ' make NUMA=1 - simulate enabled NUMA' + @echo ' make 32BIT_PHYS_ADDR_T=1 - Use 32 bit physical addresses' + +vpath %.c ../../lib + +.PHONY: clean include help -- cgit v1.3.1