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| author | Kees Cook <keescook@chromium.org> | 2016-06-07 11:05:33 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2016-07-26 14:41:47 -0700 |
| commit | f5509cc18daa7f82bcc553be70df2117c8eedc16 (patch) | |
| tree | 648605cc96e4ac412a9f5201468795574997d9bb /mm/Makefile | |
| parent | 0f60a8efe4005ab5e65ce000724b04d4ca04a199 (diff) | |
| download | linux-f5509cc18daa7f82bcc553be70df2117c8eedc16.tar.gz | |
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/Makefile | 4 |
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 |