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authorDavid Windsor <dave@nullcore.net>2017-06-10 22:50:47 -0400
committerKees Cook <keescook@chromium.org>2018-01-15 12:07:49 -0800
commit6c0c21adc742a255f0203ef76ef0ed6c8c3b0630 (patch)
treeed1261caefae3fedeb6c065c056101d7e4787e15
parent2d891fbc3bb681ba1f826e7ee70dbe38ca7465fe (diff)
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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: David 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: Kees Cook <keescook@chromium.org> Acked-by: Christoph Lameter <cl@linux.com>
-rw-r--r--mm/slab.c3
-rw-r--r--mm/slab.h3
-rw-r--r--mm/slab_common.c10
3 files changed, 10 insertions, 6 deletions
diff --git a/mm/slab.c b/mm/slab.c
index b9b0df620bb9..dd367fe17a4e 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1291,7 +1291,8 @@ void __init kmem_cache_init(void)
*/
kmalloc_caches[INDEX_NODE] = create_kmalloc_cache(
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;
setup_kmalloc_cache_index_table();
diff --git a/mm/slab.h b/mm/slab.h
index 8f3030788e01..1f013f7795c6 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -97,7 +97,8 @@ struct kmem_cache *kmalloc_slab(size_t, gfp_t);
int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
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,
size_t size, slab_flags_t flags, size_t useroffset,
size_t usersize);
diff --git a/mm/slab_common.c b/mm/slab_common.c
index a51f65408637..8ac2a6320a6c 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -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,
- 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);
if (!s)
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);
memcg_link_cache(s);
s->refcount = 1;
@@ -1098,7 +1099,8 @@ void __init setup_kmalloc_cache_index_table(void)
static void __init new_kmalloc_cache(int idx, slab_flags_t flags)
{
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)
BUG_ON(!n);
kmalloc_dma_caches[i] = create_kmalloc_cache(n,
- size, SLAB_CACHE_DMA | flags);
+ size, SLAB_CACHE_DMA | flags, 0, 0);
}
}
#endif