From: David Windsor <redacted>

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 <redacted>
[kees: merged in moved kmalloc hunks, adjust commit log]
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <redacted>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Cc: linux-xfs@vger.kernel.org
Signed-off-by: Kees Cook <redacted>
Acked-by: Christoph Lameter <redacted>
---
 mm/slab.c        |  3 ++-
 mm/slab.h        |  3 ++-
 mm/slab_common.c | 10 ++++++----
 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

@@ -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);