From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: [PATCH v2 23/30] net: Restrict unwhitelisted proto caches to size 0 Date: Mon, 28 Aug 2017 14:35:04 -0700 Message-ID: <1503956111-36652-24-git-send-email-keescook@chromium.org> References: <1503956111-36652-1-git-send-email-keescook@chromium.org> Cc: Kees Cook , "David S. Miller" , Eric Dumazet , Paolo Abeni , David Howells , netdev@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com, David Windsor To: linux-kernel@vger.kernel.org Return-path: In-Reply-To: <1503956111-36652-1-git-send-email-keescook@chromium.org> Sender: owner-linux-mm@kvack.org List-Id: netdev.vger.kernel.org Now that protocols have been annotated (the copy of icsk_ca_ops->name is of an ops field from outside the slab cache): $ git grep 'copy_.*_user.*sk.*->' caif/caif_socket.c: copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) { ipv4/raw.c: if (copy_from_user(&raw_sk(sk)->filter, optval, optlen)) ipv4/raw.c: copy_to_user(optval, &raw_sk(sk)->filter, len)) ipv4/tcp.c: if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) ipv4/tcp.c: if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len)) ipv6/raw.c: if (copy_from_user(&raw6_sk(sk)->filter, optval, optlen)) ipv6/raw.c: if (copy_to_user(optval, &raw6_sk(sk)->filter, len)) sctp/socket.c: if (copy_from_user(&sctp_sk(sk)->subscribe, optval, optlen)) sctp/socket.c: if (copy_to_user(optval, &sctp_sk(sk)->subscribe, len)) sctp/socket.c: if (copy_to_user(optval, &sctp_sk(sk)->initmsg, len)) we can switch the default proto usercopy region to size 0. Any protocols needing to add whitelisted regions must annotate the fields with the useroffset and usersize fields of struct proto. 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. Cc: "David S. Miller" Cc: Eric Dumazet Cc: Paolo Abeni Cc: David Howells Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook --- net/core/sock.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/net/core/sock.c b/net/core/sock.c index 02dab98ca3e3..c7d0afa1d0b1 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -3112,9 +3112,7 @@ int proto_register(struct proto *prot, int alloc_slab) 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, + prot->useroffset, prot->usersize, NULL); if (prot->slab == NULL) { -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org