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 91CF31B6CE9; Tue, 26 Aug 2025 12:51:09 +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=1756212669; cv=none; b=KkDnmDbUEzNftN288ihdHdyP6jWvy+ltZRxp1QULP9n05EQExK5G124FTEe+KO8TgcDXd9LSTLwguppN6mFXFCTRdi3YAlS6bN0VME8UbRT3PGwfQojefOywS+d5p8Uqr2eWp8damZA2tFE8i35x7hxRgJw1P/Q8/EYStbmWxVU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756212669; c=relaxed/simple; bh=A5GDUt7kG67QmQtp3qHalMbsARswyIyNjVSay6+QKJs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Kn6bwnf4jgfwE2Qlb3qqVgiAA83uGcGbTg6FJQdgPto+Es1PouU/WtsddIUyoYzby3WR2t43zEitKzuCoKWMu3HkwIVc5Vcz8iqZuNIe/D3+0A/TVfIfQXW+EqBKh3RyqEu1jbOZ6BvnG3MNHGPw5bvxSDTFb7peg10VcGKAFB0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vl+UydYD; 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="vl+UydYD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26389C4CEF1; Tue, 26 Aug 2025 12:51:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756212669; bh=A5GDUt7kG67QmQtp3qHalMbsARswyIyNjVSay6+QKJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vl+UydYDYTkGC0jPtzyujGnW+3TSoi9XVaE+N7s7NA1e0otij9XZdpB7UN5EoVIxZ wT0jhm/zyzTUE9Nim98Dp721U5qoAwPAmm9tEnBYPlXMPogGuDaVJsG0uGrwaP40XC W+NEiHW1NXtMBPczhVN2Sb4wdEl7K/y05INe8rM4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ma Ke , Jens Axboe Subject: [PATCH 6.6 027/587] sunvdc: Balance device refcount in vdc_port_mpgroup_check Date: Tue, 26 Aug 2025 13:02:56 +0200 Message-ID: <20250826110953.641367748@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110952.942403671@linuxfoundation.org> References: <20250826110952.942403671@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 6.6-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 @@ -956,8 +956,10 @@ 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; }