On 7/30/19 6:15 AM, Taras Kondratiuk wrote:

Commit 2753ca5d9009 ("tipc: fix uninit-value in tipc_nl_compat_doit") broke older tipc tools that use compat interface (e.g. tipc-config from tipcutils package):

% tipc-config -p operation not supported

The commit started to reject TIPC netlink compat messages that do not have attributes. It is too restrictive because some of such messages are valid (they don't need any arguments):

% grep 'tx none' include/uapi/linux/tipc_config.h #define TIPC_CMD_NOOP 0x0000 /* tx none, rx none */ #define TIPC_CMD_GET_MEDIA_NAMES 0x0002 /* tx none, rx media_name(s) */ #define TIPC_CMD_GET_BEARER_NAMES 0x0003 /* tx none, rx bearer_name(s) */ #define TIPC_CMD_SHOW_PORTS 0x0006 /* tx none, rx ultra_string */ #define TIPC_CMD_GET_REMOTE_MNG 0x4003 /* tx none, rx unsigned */ #define TIPC_CMD_GET_MAX_PORTS 0x4004 /* tx none, rx unsigned */ #define TIPC_CMD_GET_NETID 0x400B /* tx none, rx unsigned */ #define TIPC_CMD_NOT_NET_ADMIN 0xC001 /* tx none, rx none */

This patch relaxes the original fix and rejects messages without arguments only if such arguments are expected by a command (reg_type is non zero).

Fixes: 2753ca5d9009 ("tipc: fix uninit-value in tipc_nl_compat_doit") Cc: stable@vger.kernel.org Signed-off-by: Taras Kondratiuk takondra@cisco.com

Acked-by: Ying Xue ying.xue@windriver.com

---

The patch is based on v5.3-rc2.

net/tipc/netlink_compat.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c index d86030ef1232..e135d4e11231 100644 --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -55,6 +55,7 @@ struct tipc_nl_compat_msg { int rep_type; int rep_size; int req_type;

• int req_size; struct net *net; struct sk_buff *rep; struct tlv_desc *req;

@@ -257,7 +258,8 @@ static int tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd, int err; struct sk_buff *arg;

• if (msg->req_type && !TLV_CHECK_TYPE(msg->req, msg->req_type))

• if (msg->req_type && (!msg->req_size ||

• 	      !TLV_CHECK_TYPE(msg->req, msg->req_type)))
  

  return -EINVAL;

msg->rep = tipc_tlv_alloc(msg->rep_size); @@ -354,7 +356,8 @@ static int tipc_nl_compat_doit(struct tipc_nl_compat_cmd_doit *cmd, { int err;

• if (msg->req_type && !TLV_CHECK_TYPE(msg->req, msg->req_type))

• if (msg->req_type && (!msg->req_size ||

• 	      !TLV_CHECK_TYPE(msg->req, msg->req_type)))
  

  return -EINVAL;

err = __tipc_nl_compat_doit(cmd, msg); @@ -1278,8 +1281,8 @@ static int tipc_nl_compat_recv(struct sk_buff *skb, struct genl_info *info) goto send; }

• len = nlmsg_attrlen(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN);
• if (!len || !TLV_OK(msg.req, len)) {

• msg.req_size = nlmsg_attrlen(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN);
• if (msg.req_size && !TLV_OK(msg.req, msg.req_size)) { msg.rep = tipc_get_err_tlv(TIPC_CFG_NOT_SUPPORTED); err = -EOPNOTSUPP; goto send;