[PATCH] hv: utils: handle and propagate errors in kvp_register

Thorsten Blum
2026-04-14T11:10:31Z

Make kvp_register() return an error code instead of silently ignoring
failures, and propagate the error from kvp_handle_handshake() instead of
returning success.

This propagates both kzalloc_obj() and hvutil_transport_send() failures
to kvp_handle_handshake() and thus to kvp_on_msg().

Fixes: 245ba56a52a3 ("Staging: hv: Implement key/value pair (KVP)")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
drivers/hv/hv_kvp.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index 0d73daf745a7..6180ebe040ff 100644
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -93,7 +93,7 @@ static void kvp_send_key(struct work_struct *dummy);
static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
static void kvp_timeout_func(struct work_struct *dummy);
static void kvp_host_handshake_func(struct work_struct *dummy);
-static void kvp_register(int);
+static int kvp_register(int);

static DECLARE_DELAYED_WORK(kvp_timeout_work, kvp_timeout_func);
static DECLARE_DELAYED_WORK(kvp_host_handshake_work, kvp_host_handshake_func);
@@ -127,24 +127,26 @@ static void kvp_register_done(void)
hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
}

-static void
+static int
kvp_register(int reg_value)
{

struct hv_kvp_msg *kvp_msg;
char *version;
+ int ret;

kvp_msg = kzalloc_obj(*kvp_msg);
+ if (!kvp_msg)
+ return -ENOMEM;

- if (kvp_msg) {
- version = kvp_msg->body.kvp_register.version;
- kvp_msg->kvp_hdr.operation = reg_value;
- strcpy(version, HV_DRV_VERSION);
+ version = kvp_msg->body.kvp_register.version;
+ kvp_msg->kvp_hdr.operation = reg_value;
+ strcpy(version, HV_DRV_VERSION);

- hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg),
- kvp_register_done);
- kfree(kvp_msg);
- }
+ ret = hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg),
+ kvp_register_done);
+ kfree(kvp_msg);
+ return ret;
}

static void kvp_timeout_func(struct work_struct *dummy)
@@ -186,9 +188,8 @@ static int kvp_handle_handshake(struct hv_kvp_msg *msg)
*/
pr_debug("KVP: userspace daemon ver. %d connected\n",
msg->kvp_hdr.operation);
- kvp_register(dm_reg_value);

- return 0;
+ return kvp_register(dm_reg_value);
}