From a095326e2c0f33743ce8e887d5b90edf3f36cced Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 11 May 2023 11:47:09 -0400 Subject: [PATCH 1/6] net/handshake: Remove unneeded check from handshake_dup() handshake_req_submit() now verifies that the socket has a file. Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests") Reviewed-by: Simon Horman Signed-off-by: Chuck Lever Signed-off-by: Jakub Kicinski --- net/handshake/netlink.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/net/handshake/netlink.c b/net/handshake/netlink.c index 35c9c445e0b85..7ec8a76c3c8a7 100644 --- a/net/handshake/netlink.c +++ b/net/handshake/netlink.c @@ -99,9 +99,6 @@ static int handshake_dup(struct socket *sock) struct file *file; int newfd; - if (!sock->file) - return -EBADF; - file = get_file(sock->file); newfd = get_unused_fd_flags(O_CLOEXEC); if (newfd < 0) { From 7ea9c1ec66bc099b0bfba961a8a46dfe25d7d8e4 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 11 May 2023 11:47:40 -0400 Subject: [PATCH 2/6] net/handshake: Fix handshake_dup() ref counting If get_unused_fd_flags() fails, we ended up calling fput(sock->file) twice. Reported-by: Dan Carpenter Suggested-by: Paolo Abeni Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests") Signed-off-by: Chuck Lever Signed-off-by: Jakub Kicinski --- net/handshake/netlink.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/handshake/netlink.c b/net/handshake/netlink.c index 7ec8a76c3c8a7..f5dc170689d9c 100644 --- a/net/handshake/netlink.c +++ b/net/handshake/netlink.c @@ -139,15 +139,16 @@ int handshake_nl_accept_doit(struct sk_buff *skb, struct genl_info *info) goto out_complete; } err = req->hr_proto->hp_accept(req, info, fd); - if (err) + if (err) { + fput(sock->file); goto out_complete; + } trace_handshake_cmd_accept(net, req, req->hr_sk, fd); return 0; out_complete: handshake_complete(req, -EIO, NULL); - fput(sock->file); out_status: trace_handshake_cmd_accept_err(net, req, NULL, err); return err; From 7afc6d0a107ffbd448c96eb2458b9e64a5af7860 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 11 May 2023 11:48:13 -0400 Subject: [PATCH 3/6] net/handshake: Fix uninitialized local variable trace_handshake_cmd_done_err() simply records the pointer in @req, so initializing it to NULL is sufficient and safe. Reported-by: Dan Carpenter Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests") Reviewed-by: Simon Horman Signed-off-by: Chuck Lever Signed-off-by: Jakub Kicinski --- net/handshake/netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/handshake/netlink.c b/net/handshake/netlink.c index f5dc170689d9c..16a4bde648bac 100644 --- a/net/handshake/netlink.c +++ b/net/handshake/netlink.c @@ -157,8 +157,8 @@ int handshake_nl_accept_doit(struct sk_buff *skb, struct genl_info *info) int handshake_nl_done_doit(struct sk_buff *skb, struct genl_info *info) { struct net *net = sock_net(skb->sk); + struct handshake_req *req = NULL; struct socket *sock = NULL; - struct handshake_req *req; int fd, status, err; if (GENL_REQ_ATTR_CHECK(info, HANDSHAKE_A_DONE_SOCKFD)) From fc490880e39d86c65ab2bcbd357af1950fa55e48 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 11 May 2023 11:48:45 -0400 Subject: [PATCH 4/6] net/handshake: handshake_genl_notify() shouldn't ignore @flags Reported-by: Dan Carpenter Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests") Reviewed-by: Simon Horman Signed-off-by: Chuck Lever Signed-off-by: Jakub Kicinski --- net/handshake/netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/handshake/netlink.c b/net/handshake/netlink.c index 16a4bde648bac..1086653e1fada 100644 --- a/net/handshake/netlink.c +++ b/net/handshake/netlink.c @@ -48,7 +48,7 @@ int handshake_genl_notify(struct net *net, const struct handshake_proto *proto, proto->hp_handler_class)) return -ESRCH; - msg = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL); + msg = genlmsg_new(GENLMSG_DEFAULT_SIZE, flags); if (!msg) return -ENOMEM; From 1ce77c998f0415d7d9d91cb9bd7665e25c8f75f1 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 11 May 2023 11:49:17 -0400 Subject: [PATCH 5/6] net/handshake: Unpin sock->file if a handshake is cancelled If user space never calls DONE, sock->file's reference count remains elevated. Enable sock->file to be freed eventually in this case. Reported-by: Jakub Kacinski Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests") Signed-off-by: Chuck Lever Signed-off-by: Jakub Kicinski --- net/handshake/handshake.h | 1 + net/handshake/request.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/net/handshake/handshake.h b/net/handshake/handshake.h index 4dac965c99df0..8aeaadca844fd 100644 --- a/net/handshake/handshake.h +++ b/net/handshake/handshake.h @@ -31,6 +31,7 @@ struct handshake_req { struct list_head hr_list; struct rhash_head hr_rhash; unsigned long hr_flags; + struct file *hr_file; const struct handshake_proto *hr_proto; struct sock *hr_sk; void (*hr_odestruct)(struct sock *sk); diff --git a/net/handshake/request.c b/net/handshake/request.c index 94d5cef3e048b..d78d41abb3d99 100644 --- a/net/handshake/request.c +++ b/net/handshake/request.c @@ -239,6 +239,7 @@ int handshake_req_submit(struct socket *sock, struct handshake_req *req, } req->hr_odestruct = req->hr_sk->sk_destruct; req->hr_sk->sk_destruct = handshake_sk_destruct; + req->hr_file = sock->file; ret = -EOPNOTSUPP; net = sock_net(req->hr_sk); @@ -334,6 +335,9 @@ bool handshake_req_cancel(struct sock *sk) return false; } + /* Request accepted and waiting for DONE */ + fput(req->hr_file); + out_true: trace_handshake_cancel(net, req, sk); From 26fb5480a27d34975cc2b680b77af189620dd740 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 11 May 2023 11:49:50 -0400 Subject: [PATCH 6/6] net/handshake: Enable the SNI extension to work properly Enable the upper layer protocol to specify the SNI peername. This avoids the need for tlshd to use a DNS lookup, which can return a hostname that doesn't match the incoming certificate's SubjectName. Fixes: 2fd5532044a8 ("net/handshake: Add a kernel API for requesting a TLSv1.3 handshake") Reviewed-by: Simon Horman Signed-off-by: Chuck Lever Signed-off-by: Jakub Kicinski --- Documentation/netlink/specs/handshake.yaml | 4 ++++ Documentation/networking/tls-handshake.rst | 5 +++++ include/net/handshake.h | 1 + include/uapi/linux/handshake.h | 1 + net/handshake/tlshd.c | 8 ++++++++ 5 files changed, 19 insertions(+) diff --git a/Documentation/netlink/specs/handshake.yaml b/Documentation/netlink/specs/handshake.yaml index 614f1a5855114..6d89e30f5fd52 100644 --- a/Documentation/netlink/specs/handshake.yaml +++ b/Documentation/netlink/specs/handshake.yaml @@ -68,6 +68,9 @@ attribute-sets: type: nest nested-attributes: x509 multi-attr: true + - + name: peername + type: string - name: done attributes: @@ -105,6 +108,7 @@ operations: - auth-mode - peer-identity - certificate + - peername - name: done doc: Handler reports handshake completion diff --git a/Documentation/networking/tls-handshake.rst b/Documentation/networking/tls-handshake.rst index a2817a88e905f..6f5ea1646a470 100644 --- a/Documentation/networking/tls-handshake.rst +++ b/Documentation/networking/tls-handshake.rst @@ -53,6 +53,7 @@ fills in a structure that contains the parameters of the request: struct socket *ta_sock; tls_done_func_t ta_done; void *ta_data; + const char *ta_peername; unsigned int ta_timeout_ms; key_serial_t ta_keyring; key_serial_t ta_my_cert; @@ -71,6 +72,10 @@ instantiated a struct file in sock->file. has completed. Further explanation of this function is in the "Handshake Completion" sesction below. +The consumer can provide a NUL-terminated hostname in the @ta_peername +field that is sent as part of ClientHello. If no peername is provided, +the DNS hostname associated with the server's IP address is used instead. + The consumer can fill in the @ta_timeout_ms field to force the servicing handshake agent to exit after a number of milliseconds. This enables the socket to be fully closed once both the kernel and the handshake agent diff --git a/include/net/handshake.h b/include/net/handshake.h index 3352b1ab43b35..2e26e436e85f5 100644 --- a/include/net/handshake.h +++ b/include/net/handshake.h @@ -24,6 +24,7 @@ struct tls_handshake_args { struct socket *ta_sock; tls_done_func_t ta_done; void *ta_data; + const char *ta_peername; unsigned int ta_timeout_ms; key_serial_t ta_keyring; key_serial_t ta_my_cert; diff --git a/include/uapi/linux/handshake.h b/include/uapi/linux/handshake.h index 1de4d0b95325b..3d7ea58778c96 100644 --- a/include/uapi/linux/handshake.h +++ b/include/uapi/linux/handshake.h @@ -44,6 +44,7 @@ enum { HANDSHAKE_A_ACCEPT_AUTH_MODE, HANDSHAKE_A_ACCEPT_PEER_IDENTITY, HANDSHAKE_A_ACCEPT_CERTIFICATE, + HANDSHAKE_A_ACCEPT_PEERNAME, __HANDSHAKE_A_ACCEPT_MAX, HANDSHAKE_A_ACCEPT_MAX = (__HANDSHAKE_A_ACCEPT_MAX - 1) diff --git a/net/handshake/tlshd.c b/net/handshake/tlshd.c index fcbeb63b4eb16..b735f5cced2f5 100644 --- a/net/handshake/tlshd.c +++ b/net/handshake/tlshd.c @@ -31,6 +31,7 @@ struct tls_handshake_req { int th_type; unsigned int th_timeout_ms; int th_auth_mode; + const char *th_peername; key_serial_t th_keyring; key_serial_t th_certificate; key_serial_t th_privkey; @@ -48,6 +49,7 @@ tls_handshake_req_init(struct handshake_req *req, treq->th_timeout_ms = args->ta_timeout_ms; treq->th_consumer_done = args->ta_done; treq->th_consumer_data = args->ta_data; + treq->th_peername = args->ta_peername; treq->th_keyring = args->ta_keyring; treq->th_num_peerids = 0; treq->th_certificate = TLS_NO_CERT; @@ -214,6 +216,12 @@ static int tls_handshake_accept(struct handshake_req *req, ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_MESSAGE_TYPE, treq->th_type); if (ret < 0) goto out_cancel; + if (treq->th_peername) { + ret = nla_put_string(msg, HANDSHAKE_A_ACCEPT_PEERNAME, + treq->th_peername); + if (ret < 0) + goto out_cancel; + } if (treq->th_timeout_ms) { ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_TIMEOUT, treq->th_timeout_ms); if (ret < 0)