From 9409e18ffe7378d202efe1cf69989df9f67b0369 Mon Sep 17 00:00:00 2001 From: Wentao Liang Date: Tue, 28 Jul 2026 14:07:42 -0400 Subject: [PATCH] ipmi: fix refcount leak in i_ipmi_request() [ Upstream commit a3f3859cecacb64f18fd446271ece9a3b3f2d4de ] 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: stable@vger.kernel.org Fixes: b52da4054ee0 ("ipmi: Rework user message limit handling") Signed-off-by: Wentao Liang Message-ID: <20260603120634.3758747-1-vulab@iscas.ac.cn> Signed-off-by: Corey Minyard [ changed `free_ipmi_user` to `free_user` in the two added `kref_put()` calls ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- 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 37b84bfa623e..7dec2138b874 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -2331,6 +2331,10 @@ 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_user); + } return -ENOMEM; } } @@ -2373,6 +2377,10 @@ out_err: 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_user); + } } else { dev_dbg(intf->si_dev, "Send: %*ph\n", smi_msg->data_size, smi_msg->data);