[patch 036/262] mm/kvmalloc: add __alloc_size attributes for better bounds checking

Andrew Morton
2021-11-05T20:36:34Z

From: Kees Cook <keescook@chromium.org>
Subject: mm/kvmalloc: add __alloc_size attributes for better bounds checking

As already done in GrapheneOS, add the __alloc_size attribute for regular
kvmalloc interfaces, to provide additional hinting for better bounds
checking, assisting CONFIG_FORTIFY_SOURCE and other compiler
optimizations.

Link: https://lkml.kernel.org/r/20210930222704.2631604-6-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@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: Vlastimil Babka <vbabka@suse.cz>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jing Xiangfeng <jingxiangfeng@huawei.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

include/linux/slab.h | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

--- a/include/linux/slab.h~mm-kvmalloc-add-__alloc_size-attributes-for-better-bounds-checking
+++ a/include/linux/slab.h
@@ -737,21 +737,21 @@ static inline __alloc_size(1) void *kzal
return kmalloc_node(size, flags | __GFP_ZERO, node);
}

-extern void *kvmalloc_node(size_t size, gfp_t flags, int node);
-static inline void *kvmalloc(size_t size, gfp_t flags)
+extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1);
+static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags)
{
return kvmalloc_node(size, flags, NUMA_NO_NODE);
}
-static inline void *kvzalloc_node(size_t size, gfp_t flags, int node)
+static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node)
{
return kvmalloc_node(size, flags | __GFP_ZERO, node);
}
-static inline void *kvzalloc(size_t size, gfp_t flags)
+static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags)
{
return kvmalloc(size, flags | __GFP_ZERO);
}

-static inline void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
+static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
{
size_t bytes;

@@ -761,13 +761,13 @@ static inline void *kvmalloc_array(size_
return kvmalloc(bytes, flags);
}

-static inline void *kvcalloc(size_t n, size_t size, gfp_t flags)
+static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags)
{
return kvmalloc_array(n, size, flags | __GFP_ZERO);
}

-extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize,
- gfp_t flags);
+extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
+ __alloc_size(3);
extern void kvfree(const void *addr);
extern void kvfree_sensitive(const void *addr, size_t len);

_