When a caller provides a `supplied_recv` message to i_ipmi_request(),
the function increments the user's `nr_msgs` reference count. If an
error occurs later, the out_err cleanup path only frees the recv_msg
if the function allocated it itself (i.e., !supplied_recv). In the
supplied_recv case the cleanup is skipped, leaving the reference count
elevated. The caller ipmi_request_supply_msgs() does not release the
supplied_recv on error, so the reference is permanently leaked.

Fix this by explicitly reverting the reference count operations when a
supplied recv_msg with a valid user pointer is present in the error
path: decrement nr_msgs and drop the user's kref.

Cc: [email protected]
Fixes: b52da4054ee0 ("ipmi: Rework user message limit handling")
Signed-off-by: Wentao Liang <[email protected]>
---
 drivers/char/ipmi/ipmi_msghandler.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/char/ipmi/ipmi_msghandler.c 
b/drivers/char/ipmi/ipmi_msghandler.c
index 869ac87a4b6a..5b9d914cc7a9 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -2347,6 +2347,10 @@ static int i_ipmi_request(struct ipmi_user     *user,
                if (smi_msg == NULL) {
                        if (!supplied_recv)
                                ipmi_free_recv_msg(recv_msg);
+                       else if (recv_msg->user) {
+                               atomic_dec(&recv_msg->user->nr_msgs);
+                               kref_put(&recv_msg->user->refcount, 
free_ipmi_user);
+                       }
                        return -ENOMEM;
                }
        }
@@ -2420,6 +2424,10 @@ static int i_ipmi_request(struct ipmi_user     *user,
                        ipmi_free_smi_msg(smi_msg);
                if (!supplied_recv)
                        ipmi_free_recv_msg(recv_msg);
+               else if (recv_msg->user) {
+                       atomic_dec(&recv_msg->user->nr_msgs);
+                       kref_put(&recv_msg->user->refcount, free_ipmi_user);
+               }
        }
        return rv;
 }
-- 
2.34.1



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