From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794049848; b=TE7p7lZzDlmCAfsmAs0h14T0EaKLMjyEljFWCKOcXdwSaF70du81ZkXAanzmEXgFvA2R 1uAPIF4W4BM7sbWQUvNcHlXMGKOVzqA8lBBgKqWLj4vv2S/UENKgXKeRrzsWQdBnj0r/i 2ikugHFnF3juKbE0wtgAQmaOxNM4L/O84BaIIxVNbtW2ArgrZhbYa8ihDzPqq0GWRb56z jrg0cN3R4GCRmCbJAxjixX2Jvf9k1Ue3UWbZUNgf3jrtbGlPMFksAYrDvgn9+dAJKHcp7 9oVv3S8s7JoLYZEWedwVBZZLdStZ/g/P+14fz2FL+bnOCUqlaVvK++nBwE/aZBN2zAg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794049848; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=1RFdybfjjtX9OxredLn7LtYD8CjVxZNuizXzjIliqjk=; b=gind1ujxN5ZpsAOJFY73Ufh1rawZpaEcdqoaup232jIZX3YGuyRjythunLdResylZhHY QM6gYrfAD5NBMxkp6fXdryUPjQ5nhlj4oth3x+cgkANw0/E646KzncNlR9QXO3RDSFa1o 6+vyq0skc35sx9wtLaPAfhRXzmUd4tAJeZSbAmcbqPcuz2iOUDd/ZaMiHWZb501uzSRRM i2Bf3K7YzGtrQyB1aumwKZSQBvbXTeJQYN3ERTrpKl/HLErCQHj+NL+jJMujSw1y2YJe6 RmmiRwLqII0aUnaKiv6N7qvtzKQBi+lxzSiwK8oNIcS4WLhhj2okyAmZEvfCVO905dw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="CMQ2T1/E"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E37D606A326 for ; Sat, 7 Nov 2026 11:10:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=CMQ2T1/E Received: by smtp.kernel.org (Postfix) with ESMTPSA id C06201F008A1; Sat, 7 Nov 2026 11:10:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794049848; bh=1RFdybfjjtX9OxredLn7LtYD8CjVxZNuizXzjIliqjk=; h=From:To:Cc:Subject:Date; b=CMQ2T1/EfhuCDyty3O5s0mGTyKGU4PMWKEsZmJIQ1P9cq6JMrNx9rHoiUUkH+gwgW CoF+6FXTlZcr36B6o3RpcUe+EeikoMPsaOYxV95RNYPRL8eaZiK+wRmf5gb1pDmYny 5LiCXN7ymX82Oh9IJyXlYok05GVFDNod9kHqq39C7MUOWy9OnU8DLTvTg9EG91s0MN 8sV0Q2ddj/2SbjO0S3UDWusKRBVaLBBMo70aVLI+k2Eppe35kv1lB6JJwTMW9xhxLw 0wJe1zycB9v5kB/2dUQreftW9xHwEV1+KrLbQT4Tq7o78SSFbjzt/dhfjuxGINlAGt K7clgkZ9SDCvQ== From: Sasha Levin To: make_ruc2021@163.com, andi.shyti@kernel.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] i2c: acpi: Fix adapter reference leak in i2c_acpi_new_device_by_fwnode()" failed to apply to 5.15-stable tree Date: Sat, 7 Nov 2026 06:10:46 -0500 Message-ID: <20261107061046-failed-5.15-a65917d0a22f@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x a65917d0a22f9b10694853b725f9cd399fc3ef4d # git commit -s git send-email --to '' --in-reply-to '20261107061046-failed-5.15-a65917d0a22f@kernel.org' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From a65917d0a22f9b10694853b725f9cd399fc3ef4d Mon Sep 17 00:00:00 2001 From: Ma Ke Date: Mon, 12 Oct 2026 09:34:21 +0800 Subject: [PATCH] i2c: acpi: Fix adapter reference leak in i2c_acpi_new_device_by_fwnode() i2c_acpi_new_device_by_fwnode() obtains an i2c_adapter through i2c_acpi_find_adapter_by_handle(). That helper uses bus_find_device() internally, so it returns the adapter with a reference held: adapter = i2c_verify_adapter(dev); if (!adapter) put_device(dev); return adapter; The reference is only put on the failure path inside that helper. The caller owns it otherwise. i2c_acpi_new_device_by_fwnode() never drops it, neither on the -EPROBE_DEFER path nor after i2c_new_client_device(), so every call leaks one reference on the adapter and the adapter can never be released. i2c_new_client_device() does not consume that reference. It registers the new client with the adapter as its parent, and device_add() takes its own reference on the parent, which device_del() releases when the client goes away. The reference obtained by the lookup is a separate one and has to be dropped here. i2c_acpi_notify() in the same file already does exactly this. It takes the adapter from the same helper, registers the client through i2c_acpi_register_device(), which calls i2c_new_client_device(), and then puts the reference. i2c_new_client_device() gives the client its own reference on the adapter, so ours can be dropped unconditionally. Found by code review. Fixes: 605f8fc22442 ("i2c: core: Add new i2c_acpi_new_device helper function") Signed-off-by: Ma Ke Cc: # v4.12+ Signed-off-by: Andi Shyti Link: https://patch.msgid.link/20261012013421.3597430-1-make_ruc2021@163.com --- drivers/i2c/i2c-core-acpi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c index 703588e9990a6..84841ed134874 100644 --- a/drivers/i2c/i2c-core-acpi.c +++ b/drivers/i2c/i2c-core-acpi.c @@ -549,6 +549,7 @@ struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode, { struct i2c_acpi_lookup lookup; struct i2c_adapter *adapter; + struct i2c_client *client; struct acpi_device *adev; LIST_HEAD(resource_list); int ret; @@ -576,7 +577,10 @@ struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode, if (!adapter) return ERR_PTR(-EPROBE_DEFER); - return i2c_new_client_device(adapter, info); + client = i2c_new_client_device(adapter, info); + put_device(&adapter->dev); + + return client; } EXPORT_SYMBOL_GPL(i2c_acpi_new_device_by_fwnode); -- 2.53.0