From b1f90d263a3b2b6ca1bc49b3542aaf13e6df7eba Mon Sep 17 00:00:00 2001 From: =?utf8?q?H=C3=A5kon=20Bugge?= Date: Mon, 16 Dec 2019 13:04:36 +0100 Subject: [PATCH] RDMA/netlink: Do not always generate an ACK for some netlink operations MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit a242c36951ecd24bc16086940dbe6b522205c461 upstream. In rdma_nl_rcv_skb(), the local variable err is assigned the return value of the supplied callback function, which could be one of ib_nl_handle_resolve_resp(), ib_nl_handle_set_timeout(), or ib_nl_handle_ip_res_resp(). These three functions all return skb->len on success. rdma_nl_rcv_skb() is merely a copy of netlink_rcv_skb(). The callback functions used by the latter have the convention: "Returns 0 on success or a negative error code". In particular, the statement (equal for both functions): if (nlh->nlmsg_flags & NLM_F_ACK || err) implies that rdma_nl_rcv_skb() always will ack a message, independent of the NLM_F_ACK being set in nlmsg_flags or not. The fix could be to change the above statement, but it is better to keep the two *_rcv_skb() functions equal in this respect and instead change the three callback functions in the rdma subsystem to the correct convention. Fixes: 2ca546b92a02 ("IB/sa: Route SA pathrecord query through netlink") Fixes: ae43f8286730 ("IB/core: Add IP to GID netlink offload") Link: https://lore.kernel.org/r/20191216120436.3204814-1-haakon.bugge@oracle.com Suggested-by: Mark Haywood Signed-off-by: HÃ¥kon Bugge Tested-by: Mark Haywood Reviewed-by: Leon Romanovsky Reviewed-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/core/addr.c | 2 +- drivers/infiniband/core/sa_query.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c index 606fa6d..1753a98 100644 --- a/drivers/infiniband/core/addr.c +++ b/drivers/infiniband/core/addr.c @@ -139,7 +139,7 @@ int ib_nl_handle_ip_res_resp(struct sk_buff *skb, if (ib_nl_is_good_ip_resp(nlh)) ib_nl_process_good_ip_rsep(nlh); - return skb->len; + return 0; } static int ib_nl_ip_send_msg(struct rdma_dev_addr *dev_addr, diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c index 17fc293..bddb543 100644 --- a/drivers/infiniband/core/sa_query.c +++ b/drivers/infiniband/core/sa_query.c @@ -1068,7 +1068,7 @@ int ib_nl_handle_set_timeout(struct sk_buff *skb, } settimeout_out: - return skb->len; + return 0; } static inline int ib_nl_is_good_resolve_resp(const struct nlmsghdr *nlh) @@ -1139,7 +1139,7 @@ int ib_nl_handle_resolve_resp(struct sk_buff *skb, } resp_out: - return skb->len; + return 0; } static void free_sm_ah(struct kref *kref) -- 2.7.4