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authorAlexander Potapenko <glider@google.com>2021-02-26 04:19:11 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-26 20:41:02 +0300
commitd3fb45f370d927224af35d22d34ea465884afec8 (patch)
tree2524c69674a4ad0f2d65e6c48d37dcdd20c61318 /include
parentd438fabce7860df3cb9337776be6f90b59ced8ed (diff)
downloadlinux-d3fb45f370d927224af35d22d34ea465884afec8.tar.xz
mm, kfence: insert KFENCE hooks for SLAB
Inserts KFENCE hooks into the SLAB allocator. To pass the originally requested size to KFENCE, add an argument 'orig_size' to slab_alloc*(). The additional argument is required to preserve the requested original size for kmalloc() allocations, which uses size classes (e.g. an allocation of 272 bytes will return an object of size 512). Therefore, kmem_cache::size does not represent the kmalloc-caller's requested size, and we must introduce the argument 'orig_size' to propagate the originally requested size to KFENCE. Without the originally requested size, we would not be able to detect out-of-bounds accesses for objects placed at the end of a KFENCE object page if that object is not equal to the kmalloc-size class it was bucketed into. When KFENCE is disabled, there is no additional overhead, since slab_alloc*() functions are __always_inline. Link: https://lkml.kernel.org/r/20201103175841.3495947-5-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Co-developed-by: Marco Elver <elver@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/slab_def.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index 9eb430c163c2..3aa5e1e73ab6 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -2,6 +2,7 @@
#ifndef _LINUX_SLAB_DEF_H
#define _LINUX_SLAB_DEF_H
+#include <linux/kfence.h>
#include <linux/reciprocal_div.h>
/*
@@ -114,6 +115,8 @@ static inline unsigned int obj_to_index(const struct kmem_cache *cache,
static inline int objs_per_slab_page(const struct kmem_cache *cache,
const struct page *page)
{
+ if (is_kfence_address(page_address(page)))
+ return 1;
return cache->num;
}