[PATCH 4.19 050/190] Drivers: hv: kvp: Fix the recent regression caused by incorrect clean-up

Greg Kroah-Hartman
2019-09-13T13:31:50Z

[ Upstream commit e670de54c813b5bc3672dd1c67871dc60e9206f4 ]

In kvp_send_key(), we do need call process_ib_ipinfo() if
message->kvp_hdr.operation is KVP_OP_GET_IP_INFO, because it turns out
the userland hv_kvp_daemon needs the info of operation, adapter_id and
addr_family. With the incorrect fc62c3b1977d, the host can't get the
VM's IP via KVP.

And, fc62c3b1977d added a "break;", but actually forgot to initialize
the key_size/value in the case of KVP_OP_SET, so the default key_size of
0 is passed to the kvp daemon, and the pool files
/var/lib/hyperv/.kvp_pool_* can't be updated.

This patch effectively rolls back the previous fc62c3b1977d, and
correctly fixes the "this statement may fall through" warnings.

This patch is tested on WS 2012 R2 and 2016.

Fixes: fc62c3b1977d ("Drivers: hv: kvp: Fix two "this statement may fall through" warnings")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hv/hv_kvp.c | 26 ++++++++++++++++++++++----
1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index a7513a8a8e372..d6106e1a0d4af 100644
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -353,6 +353,9 @@ static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)

out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;

+ /* fallthrough */
+
+ case KVP_OP_GET_IP_INFO:
utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
MAX_ADAPTER_ID_SIZE,
UTF16_LITTLE_ENDIAN,
@@ -405,7 +408,11 @@ kvp_send_key(struct work_struct *dummy)
process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
break;
case KVP_OP_GET_IP_INFO:
- /* We only need to pass on message->kvp_hdr.operation. */
+ /*
+ * We only need to pass on the info of operation, adapter_id
+ * and addr_family to the userland kvp daemon.
+ */
+ process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
break;
case KVP_OP_SET:
switch (in_msg->body.kvp_set.data.value_type) {
@@ -446,9 +453,9 @@ kvp_send_key(struct work_struct *dummy)

}

- break;
-
- case KVP_OP_GET:
+ /*
+ * The key is always a string - utf16 encoding.
+ */
message->body.kvp_set.data.key_size =
utf16s_to_utf8s(
(wchar_t *)in_msg->body.kvp_set.data.key,
@@ -456,6 +463,17 @@ kvp_send_key(struct work_struct *dummy)
UTF16_LITTLE_ENDIAN,
message->body.kvp_set.data.key,
HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
+
+ break;
+
+ case KVP_OP_GET:
+ message->body.kvp_get.data.key_size =
+ utf16s_to_utf8s(
+ (wchar_t *)in_msg->body.kvp_get.data.key,
+ in_msg->body.kvp_get.data.key_size,
+ UTF16_LITTLE_ENDIAN,
+ message->body.kvp_get.data.key,
+ HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
break;

case KVP_OP_DELETE:
--
2.20.1