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/Kconfig.include | 78 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 scripts/Kconfig.include (limited to 'scripts/Kconfig.include') diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include new file mode 100644 index 000000000..fc10671c2 --- /dev/null +++ b/scripts/Kconfig.include @@ -0,0 +1,78 @@ +# SPDX-License-Identifier: GPL-2.0-only +# Kconfig helper macros + +# Convenient variables +comma := , +quote := " +squote := ' +empty := +space := $(empty) $(empty) +dollar := $ +right_paren := ) +left_paren := ( + +# $(if-success,,,) +# Return if exits with 0, otherwise. +if-success = $(shell,{ $(1); } >/dev/null 2>&1 && echo "$(2)" || echo "$(3)") + +# $(success,) +# Return y if exits with 0, n otherwise +success = $(if-success,$(1),y,n) + +# $(failure,) +# Return n if exits with 0, y otherwise +failure = $(if-success,$(1),n,y) + +# $(cc-option,) +# Return y if the compiler supports , n otherwise +cc-option = $(success,trap "rm -rf .tmp_$$" EXIT; mkdir .tmp_$$; $(CC) -Werror $(CLANG_FLAGS) $(1) -c -x c /dev/null -o .tmp_$$/tmp.o) + +# $(ld-option,) +# Return y if the linker supports , n otherwise +ld-option = $(success,$(LD) -v $(1)) + +# $(as-instr,) +# Return y if the assembler supports , n otherwise +as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) $(2) -Wa$(comma)--fatal-warnings -c -x assembler-with-cpp -o /dev/null -) +as-instr64 = $(as-instr,$(1),$(m64-flag)) + +# check if $(CC) and $(LD) exist +$(error-if,$(failure,command -v $(CC)),C compiler '$(CC)' not found) +$(error-if,$(failure,command -v $(LD)),linker '$(LD)' not found) + +# Get the C compiler name, version, and error out if it is not supported. +cc-info := $(shell,$(srctree)/scripts/cc-version.sh $(CC)) +$(error-if,$(success,test -z "$(cc-info)"),Sorry$(comma) this C compiler is not supported.) +cc-name := $(shell,set -- $(cc-info) && echo $1) +cc-version := $(shell,set -- $(cc-info) && echo $2) + +# Get the assembler name, version, and error out if it is not supported. +as-info := $(shell,$(srctree)/scripts/as-version.sh $(CC) $(CLANG_FLAGS)) +$(error-if,$(success,test -z "$(as-info)"),Sorry$(comma) this assembler is not supported.) +as-name := $(shell,set -- $(as-info) && echo $1) +as-version := $(shell,set -- $(as-info) && echo $2) + +# Get the linker name, version, and error out if it is not supported. +ld-info := $(shell,$(srctree)/scripts/ld-version.sh $(LD)) +$(error-if,$(success,test -z "$(ld-info)"),Sorry$(comma) this linker is not supported.) +ld-name := $(shell,set -- $(ld-info) && echo $1) +ld-version := $(shell,set -- $(ld-info) && echo $2) + +# machine bit flags +# $(m32-flag): -m32 if the compiler supports it, or an empty string otherwise. +# $(m64-flag): -m64 if the compiler supports it, or an empty string otherwise. +cc-option-bit = $(if-success,$(CC) -Werror $(1) -E -x c /dev/null -o /dev/null,$(1)) +m32-flag := $(cc-option-bit,-m32) +m64-flag := $(cc-option-bit,-m64) + +# Test whether the compiler can link userspace applications +cc_can_link_user = $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(1)) + +rustc-version := $(shell,$(srctree)/scripts/rustc-version.sh $(RUSTC)) +rustc-llvm-version := $(shell,$(srctree)/scripts/rustc-llvm-version.sh $(RUSTC)) + +# $(rustc-option,) +# Return y if the Rust compiler supports , n otherwise +# If you are testing for unstable features, consider testing RUSTC_VERSION +# instead, as features may have different completeness while available. +rustc-option = $(success,trap "rm -rf .tmp_$$" EXIT; mkdir .tmp_$$; $(RUSTC) $(1) --crate-type=rlib /dev/null --out-dir=.tmp_$$ -o .tmp_$$/tmp.rlib) -- cgit v1.3.1