From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ECDA335CEB3; Tue, 26 Aug 2025 14:34:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756218864; cv=none; b=a5eD9rnQTgue+snLN9LEADLBQT65h0FE8w7T4TokOXjx1k3Zy2WV6JFhpz9ZSs7GqurVe150yH2SJyrSHE/VT0bvDEEImnrqQS6EtQfIPH6jykRYBWrzBIx2QKx+vTFiYd3iP5TgTFIT7c/WDSN90CkVzfJjRAVyMx4GZArJX3g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756218864; c=relaxed/simple; bh=0qjg/4704ParXVyGPBMCnYiEQsRlKcn60Yjr4GGUCjA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qeT5Cn7SrvAoZ1/9sCnz7cfogbntee3By6IVeIRNc+WGrjIDZPyFO1wr137IxZqZRgN/Yc0mY+Gi1/Yn8oW1ixof8Q7qf2w3lNeScqHn5IStO1AZ/teoKo8x4U3NaTME4hyy8FC2svB769Xg/uXraUnq4YfJ4VZzWvvv9ESJzNY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=I+AqHig3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="I+AqHig3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7306BC4CEF1; Tue, 26 Aug 2025 14:34:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756218863; bh=0qjg/4704ParXVyGPBMCnYiEQsRlKcn60Yjr4GGUCjA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I+AqHig3cCH1UmpUD9luNp1itCOli95oMrjXQcebG9vq/J/LubDc9jV2LolAst/+K 6qNfVjxxkTe5kOsTuewqvy034KqpGvvXjbeHUG3nicuI0/qkjPPYMXPbXVj4zWCBJv jdoim3YnThevUQsYDr2fflLMPTba90U+x5zWj+RU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ma Ke , Jens Axboe Subject: [PATCH 5.4 163/403] sunvdc: Balance device refcount in vdc_port_mpgroup_check Date: Tue, 26 Aug 2025 13:08:09 +0200 Message-ID: <20250826110911.394681255@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110905.607690791@linuxfoundation.org> References: <20250826110905.607690791@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ma Ke commit 63ce53724637e2e7ba51fe3a4f78351715049905 upstream. Using device_find_child() to locate a probed virtual-device-port node causes a device refcount imbalance, as device_find_child() internally calls get_device() to increment the device’s reference count before returning its pointer. vdc_port_mpgroup_check() directly returns true upon finding a matching device without releasing the reference via put_device(). We should call put_device() to decrement refcount. As comment of device_find_child() says, 'NOTE: you will need to drop the reference with put_device() after use'. Found by code review. Cc: stable@vger.kernel.org Fixes: 3ee70591d6c4 ("sunvdc: prevent sunvdc panic when mpgroup disk added to guest domain") Signed-off-by: Ma Ke Link: https://lore.kernel.org/r/20250719075856.3447953-1-make24@iscas.ac.cn Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/sunvdc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/block/sunvdc.c +++ b/drivers/block/sunvdc.c @@ -967,8 +967,10 @@ static bool vdc_port_mpgroup_check(struc dev = device_find_child(vdev->dev.parent, &port_data, vdc_device_probed); - if (dev) + if (dev) { + put_device(dev); return true; + } return false; }