Commit 6c0c21ad authored by David Windsor's avatar David Windsor Committed by Kees Cook

usercopy: Mark kmalloc caches as usercopy caches

Mark the kmalloc slab caches as entirely whitelisted. These caches
are frequently used to fulfill kernel allocations that contain data
to be copied to/from userspace. Internal-only uses are also common,
but are scattered in the kernel. For now, mark all the kmalloc caches
as whitelisted.

This patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY
whitelisting code in the last public patch of grsecurity/PaX based on my
understanding of the code. Changes or omissions from the original code are
mine and don't reflect the original grsecurity/PaX code.
Signed-off-by: default avatarDavid Windsor <dave@nullcore.net>
[kees: merged in moved kmalloc hunks, adjust commit log]
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Cc: linux-xfs@vger.kernel.org
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarChristoph Lameter <cl@linux.com>
parent 2d891fbc
...@@ -1291,7 +1291,8 @@ void __init kmem_cache_init(void) ...@@ -1291,7 +1291,8 @@ void __init kmem_cache_init(void)
*/ */
kmalloc_caches[INDEX_NODE] = create_kmalloc_cache( kmalloc_caches[INDEX_NODE] = create_kmalloc_cache(
kmalloc_info[INDEX_NODE].name, kmalloc_info[INDEX_NODE].name,
kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS); kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS,
0, kmalloc_size(INDEX_NODE));
slab_state = PARTIAL_NODE; slab_state = PARTIAL_NODE;
setup_kmalloc_cache_index_table(); setup_kmalloc_cache_index_table();
......
...@@ -97,7 +97,8 @@ struct kmem_cache *kmalloc_slab(size_t, gfp_t); ...@@ -97,7 +97,8 @@ struct kmem_cache *kmalloc_slab(size_t, gfp_t);
int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags); int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size, extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
slab_flags_t flags); slab_flags_t flags, size_t useroffset,
size_t usersize);
extern void create_boot_cache(struct kmem_cache *, const char *name, extern void create_boot_cache(struct kmem_cache *, const char *name,
size_t size, slab_flags_t flags, size_t useroffset, size_t size, slab_flags_t flags, size_t useroffset,
size_t usersize); size_t usersize);
......
...@@ -937,14 +937,15 @@ void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t siz ...@@ -937,14 +937,15 @@ void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t siz
} }
struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size, struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
slab_flags_t flags) slab_flags_t flags, size_t useroffset,
size_t usersize)
{ {
struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT); struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
if (!s) if (!s)
panic("Out of memory when creating slab %s\n", name); panic("Out of memory when creating slab %s\n", name);
create_boot_cache(s, name, size, flags, 0, size); create_boot_cache(s, name, size, flags, useroffset, usersize);
list_add(&s->list, &slab_caches); list_add(&s->list, &slab_caches);
memcg_link_cache(s); memcg_link_cache(s);
s->refcount = 1; s->refcount = 1;
...@@ -1098,7 +1099,8 @@ void __init setup_kmalloc_cache_index_table(void) ...@@ -1098,7 +1099,8 @@ void __init setup_kmalloc_cache_index_table(void)
static void __init new_kmalloc_cache(int idx, slab_flags_t flags) static void __init new_kmalloc_cache(int idx, slab_flags_t flags)
{ {
kmalloc_caches[idx] = create_kmalloc_cache(kmalloc_info[idx].name, kmalloc_caches[idx] = create_kmalloc_cache(kmalloc_info[idx].name,
kmalloc_info[idx].size, flags); kmalloc_info[idx].size, flags, 0,
kmalloc_info[idx].size);
} }
/* /*
...@@ -1139,7 +1141,7 @@ void __init create_kmalloc_caches(slab_flags_t flags) ...@@ -1139,7 +1141,7 @@ void __init create_kmalloc_caches(slab_flags_t flags)
BUG_ON(!n); BUG_ON(!n);
kmalloc_dma_caches[i] = create_kmalloc_cache(n, kmalloc_dma_caches[i] = create_kmalloc_cache(n,
size, SLAB_CACHE_DMA | flags); size, SLAB_CACHE_DMA | flags, 0, 0);
} }
} }
#endif #endif
......
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