From nobody Mon Jun 8 07:24:34 2026 Received: from cstnet.cn (smtp81.cstnet.cn [159.226.251.81]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8651446AEEA; Wed, 3 Jun 2026 12:06:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.81 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780488411; cv=none; b=RQcgWBIwmIAbFwPcBHdUPDH2+VRITCBCQjO847AiOnXGzlBeHl8AuNgR9N8H1jn2omiXIviptavakA2s+u5MN9Enuw9bThd/ELSMv70zKOlwcpAN/BmnbtIEq5vG1GKx/Rma7Odd++zdDGmHC3cSSQRDiKq6ENvnDKBNSluNwLc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780488411; c=relaxed/simple; bh=JizyUJtj9l47MDABYPY2Ol/uBdvkPaKWospKIlUIbw8=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=hEpJCO+DJYA3CoZzyR8e411vQoKMB4B6fRZnu5g4vZm9ZDyWTHclAIQ/ao7kR0NyHMNY0AYedHDMRqszsfmisxge0KNK1nMTxRjOCpHnqRxMUZtZFwP8dm+zoVsb21eanJdLNPjFo4HTdOujURdVXCqui7vRrEjHKSYZiNB+S1g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.81 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from dfae2b116770.home.arpa (unknown [36.110.52.2]) by APP-03 (Coremail) with SMTP id rQCowACHa+LUGCBq2rWAEw--.4908S2; Wed, 03 Jun 2026 20:06:44 +0800 (CST) From: Wentao Liang To: corey@minyard.net Cc: openipmi-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org, Wentao Liang , stable@vger.kernel.org Subject: [PATCH] ipmi: fix refcount leak in i_ipmi_request() Date: Wed, 3 Jun 2026 12:06:34 +0000 Message-Id: <20260603120634.3758747-1-vulab@iscas.ac.cn> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: rQCowACHa+LUGCBq2rWAEw--.4908S2 X-Coremail-Antispam: 1UD129KBjvJXoW7ZFWDWFy3tr1rXFWrKFyDZFb_yoW8Cr17pF 43CryYyF4FqF12yasxXry8XF93uayftr98WrWDt3s7Zw1agwna9F10kw1agFy7AFWkXF43 XrsxG3y5CF15X37anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkC14x267AKxVWUJVW8JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r4j6ryUM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xII jxv20xvE14v26r126r1DMcIj6I8E87Iv67AKxVW8Jr0_Cr1UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc7CjxVAaw2AFwI0_ JF0_Jw1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67 AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1DMIIY rxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14 v26r1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8 JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfU5ku4UU UUU X-CM-SenderInfo: pyxotu46lvutnvoduhdfq/1tbiBwwHA2of-lBevgAAs0 Content-Type: text/plain; charset="utf-8" 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 --- 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_m= sghandler.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 =3D=3D 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; } --=20 2.34.1