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| author | Kees Cook <keescook@chromium.org> | 2016-06-07 11:05:33 -0700 |
|---|---|---|
| committer | Sami Tolvanen <samitolvanen@google.com> | 2016-09-06 15:53:36 +0000 |
| commit | d677b3104d3c8e927211f20083a6c2e97e003b87 (patch) | |
| tree | 71c92b3b1f79d7f6d2a46b5c19d35a547b29b24c /mm/Makefile | |
| parent | c30d7340ee0b167a45cd8d6d5c48add8f62db9a5 (diff) | |
BACKPORT: 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>
Change-Id: Iff3b5f1ddb04acd99ccf9a9046c7797363962b2a
(cherry picked from commit f5509cc18daa7f82bcc553be70df2117c8eedc16)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
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 2ed43191fc3b..8b532c94008f 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -5,6 +5,9 @@ KASAN_SANITIZE_slab_common.o := n KASAN_SANITIZE_slub.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 \ @@ -81,3 +84,4 @@ obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o obj-$(CONFIG_USERFAULTFD) += userfaultfd.o obj-$(CONFIG_IDLE_PAGE_TRACKING) += page_idle.o obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o +obj-$(CONFIG_HARDENED_USERCOPY) += usercopy.o |