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authorDavid Windsor <dave@nullcore.net>2017-06-10 22:50:42 -0400
committerKees Cook <keescook@chromium.org>2018-01-15 12:07:58 -0800
commit30c2c9f158f6c9cef41e916d1c7c11097df4befb (patch)
treed03ac031c75ba6d85871fd1a5cd0ec8ddd2ebf16 /net
parent0afe76e88c57d91ef5697720aed380a339e3df70 (diff)
downloadop-kernel-dev-30c2c9f158f6c9cef41e916d1c7c11097df4befb.zip
op-kernel-dev-30c2c9f158f6c9cef41e916d1c7c11097df4befb.tar.gz
net: Define usercopy region in struct proto slab cache
In support of usercopy hardening, this patch defines a region in the struct proto slab cache in which userspace copy operations are allowed. Some protocols need to copy objects to/from userspace, and they can declare the region via their proto structure with the new usersize and useroffset fields. Initially, if no region is specified (usersize == 0), the entire field is marked as whitelisted. This allows protocols to be whitelisted in subsequent patches. Once all protocols have been annotated, the full-whitelist default can be removed. This region is known as the slab cache's usercopy region. Slab caches can now check that each dynamically sized copy operation involving cache-managed memory falls entirely within the slab's usercopy region. 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: adjust commit log, split off per-proto patches] [kees: add logic for by-default full-whitelist] Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'net')
-rw-r--r--net/core/sock.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/net/core/sock.c b/net/core/sock.c
index c0b5b2f..261e6db 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -3151,8 +3151,12 @@ static int req_prot_init(const struct proto *prot)
int proto_register(struct proto *prot, int alloc_slab)
{
if (alloc_slab) {
- prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
+ prot->slab = kmem_cache_create_usercopy(prot->name,
+ prot->obj_size, 0,
SLAB_HWCACHE_ALIGN | prot->slab_flags,
+ prot->usersize ? prot->useroffset : 0,
+ prot->usersize ? prot->usersize
+ : prot->obj_size,
NULL);
if (prot->slab == NULL) {
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