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/powerpc/lib/Makefile | 75 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 arch/powerpc/lib/Makefile (limited to 'arch/powerpc/lib/Makefile') diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile new file mode 100644 index 000000000..b1b7a1419 --- /dev/null +++ b/arch/powerpc/lib/Makefile @@ -0,0 +1,75 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for ppc-specific library files.. +# + +CFLAGS_code-patching.o += -fno-stack-protector +CFLAGS_feature-fixups.o += -fno-stack-protector + +CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE) + +KASAN_SANITIZE_code-patching.o := n +KASAN_SANITIZE_feature-fixups.o := n +# restart_table.o contains functions called in the NMI interrupt path +# which can be in real mode. Disable KASAN. +KASAN_SANITIZE_restart_table.o := n +KCSAN_SANITIZE_code-patching.o := n +KCSAN_SANITIZE_feature-fixups.o := n + +ifdef CONFIG_KASAN +CFLAGS_code-patching.o += -DDISABLE_BRANCH_PROFILING +CFLAGS_feature-fixups.o += -DDISABLE_BRANCH_PROFILING +endif + +CFLAGS_code-patching.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) +CFLAGS_feature-fixups.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) + +obj-y += code-patching.o feature-fixups.o pmem.o + +obj-$(CONFIG_CODE_PATCHING_SELFTEST) += test-code-patching.o + +ifndef CONFIG_KASAN +obj-y += string.o memcmp_$(BITS).o +obj-$(CONFIG_PPC32) += strlen_32.o +endif + +obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o + +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o + +# See corresponding test in arch/powerpc/Makefile +# 64-bit linker creates .sfpr on demand for final link (vmlinux), +# so it is only needed for modules, and only for older linkers which +# do not support --save-restore-funcs +ifndef CONFIG_LD_IS_BFD +always-$(CONFIG_PPC64) += crtsavres.o +endif + +obj-$(CONFIG_PPC_BOOK3S_64) += copyuser_power7.o copypage_power7.o \ + memcpy_power7.o restart_table.o + +obj64-y += copypage_64.o copyuser_64.o mem_64.o hweight_64.o \ + memcpy_64.o copy_mc_64.o + +ifdef CONFIG_PPC_QUEUED_SPINLOCKS +obj-$(CONFIG_SMP) += qspinlock.o +else +obj64-$(CONFIG_SMP) += locks.o +endif + +obj64-$(CONFIG_ALTIVEC) += vmx-helper.o +obj64-$(CONFIG_KPROBES_SANITY_TEST) += test_emulate_step.o \ + test_emulate_step_exec_instr.o + +obj-y += checksum_$(BITS).o string_$(BITS).o + +obj-y += sstep.o +obj-$(CONFIG_PPC_FPU) += ldstfp.o +obj64-y += quad.o + +obj-$(CONFIG_PPC_LIB_RHEAP) += rheap.o + +obj-$(CONFIG_FTR_FIXUP_SELFTEST) += feature-fixups-test.o + +obj-$(CONFIG_PPC64) += $(obj64-y) -- cgit v1.3.1