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authorKees Cook <keescook@chromium.org>2016-06-07 20:05:33 +0200
committerKees Cook <keescook@chromium.org>2016-07-26 23:41:47 +0200
commitf5509cc18daa7f82bcc553be70df2117c8eedc16 (patch)
tree648605cc96e4ac412a9f5201468795574997d9bb /mm/Makefile
parentmm: Implement stack frame object validation (diff)
downloadlinux-f5509cc18daa7f82bcc553be70df2117c8eedc16.tar.xz
linux-f5509cc18daa7f82bcc553be70df2117c8eedc16.zip
mm: Hardened usercopy
This is the start of porting PAX_USERCOPY into the mainline kernel. This is the first set of features, controlled by CONFIG_HARDENED_USERCOPY. The work is based on code by PaX Team and Brad Spengler, and an earlier port from Casey Schaufler. Additional non-slab page tests are from Rik van Riel. This patch contains the logic for validating several conditions when performing copy_to_user() and copy_from_user() on the kernel object being copied to/from: - address range doesn't wrap around - address range isn't NULL or zero-allocated (with a non-zero copy size) - if on the slab allocator: - object size must be less than or equal to copy size (when check is implemented in the allocator, which appear in subsequent patches) - otherwise, object must not span page allocations (excepting Reserved and CMA ranges) - if on the stack - object must not extend before/after the current process stack - object must be contained by a valid stack frame (when there is arch/build support for identifying stack frames) - object must not overlap with kernel text Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'mm/Makefile')
-rw-r--r--mm/Makefile4
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/Makefile b/mm/Makefile
index 78c6f7dedb83..32d37247c7e5 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -21,6 +21,9 @@ KCOV_INSTRUMENT_memcontrol.o := n
KCOV_INSTRUMENT_mmzone.o := n
KCOV_INSTRUMENT_vmstat.o := n
+# Since __builtin_frame_address does work as used, disable the warning.
+CFLAGS_usercopy.o += $(call cc-disable-warning, frame-address)
+
mmu-y := nommu.o
mmu-$(CONFIG_MMU) := gup.o highmem.o memory.o mincore.o \
mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \
@@ -99,3 +102,4 @@ obj-$(CONFIG_USERFAULTFD) += userfaultfd.o
obj-$(CONFIG_IDLE_PAGE_TRACKING) += page_idle.o
obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o
obj-$(CONFIG_DEBUG_PAGE_REF) += debug_page_ref.o
+obj-$(CONFIG_HARDENED_USERCOPY) += usercopy.o