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 --- scripts/Makefile.thinlto | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 scripts/Makefile.thinlto (limited to 'scripts/Makefile.thinlto') diff --git a/scripts/Makefile.thinlto b/scripts/Makefile.thinlto new file mode 100644 index 000000000..bb83f13f3 --- /dev/null +++ b/scripts/Makefile.thinlto @@ -0,0 +1,40 @@ +PHONY := __default +__default: + +include include/config/auto.conf +include $(srctree)/scripts/Kbuild.include +include $(srctree)/scripts/Makefile.lib + +native-objs := $(patsubst %.o,%.thinlto-native.o,$(call read-file, vmlinux.thinlto-index)) + +__default: $(native-objs) + +# Generate .thinlto-native.o (obj) from .o (bitcode) and .thinlto.bc (summary) files +# --------------------------------------------------------------------------- +quiet_cmd_cc_o_bc = CC $(quiet_modtag) $@ + be_flags = $(shell sed -n '/saved_c_flags_/s/.*:= //p' \ + $(dir $(<)).$(notdir $(<)).cmd) + cmd_cc_o_bc = \ + $(CC) $(be_flags) -x ir -fno-lto -Wno-unused-command-line-argument \ + -fthinlto-index=$(word 2, $^) -c -o $@ $< + +targets += $(native-objs) +$(native-objs): %.thinlto-native.o: %.o %.o.thinlto.bc FORCE + $(call if_changed,cc_o_bc) + +# Add FORCE to the prerequisites of a target to force it to be always rebuilt. +# --------------------------------------------------------------------------- + +PHONY += FORCE +FORCE: + +# Read all saved command lines and dependencies for the $(targets) we +# may be building above, using $(if_changed{,_dep}). As an +# optimization, we don't need to read them if the target does not +# exist, we will rebuild anyway in that case. + +existing-targets := $(wildcard $(sort $(targets))) + +-include $(foreach f, $(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) + +.PHONY: $(PHONY) -- cgit v1.3.1