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 BBE4421ABDC; Tue, 26 Aug 2025 13:49:02 +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=1756216142; cv=none; b=G/zTPzT0yP9yIcmVhXd63cE7R2qzqHY+q0TMZFvvx8ukWBj1BeB94htE1rKlZoQfirCWARIl/sj/qrtCkBMb88Bx2+DazxZu9K0twkpsM9q3N2x3vED59tTPU0K0JtlahdaTGEvxRNabeTJTO3r1AYcvwi6PmlE5p5AV05EICs8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756216142; c=relaxed/simple; bh=xkmVAjN+vkVTiyrNUpM7dZgjvNWAWnBI3PRoNu3Zwaw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=U9E+gZ3yHqbUxj3o2JQz4Y3+xCSHg/hcq5MYbHt/pVD4fBX6K14DIuk2b2zc/P5F5zUwB8Trponj4Cs6Idd+ipQCrrtISMutXsDqe5ZQeP2VP2Sj/+ANHJJmiWrSWWvMP3T0tnTHt4fyjx+REXMLeEYypRGbkBAPg4fvj2/fhyA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Fqvm1kNv; 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="Fqvm1kNv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9534C4CEF1; Tue, 26 Aug 2025 13:49:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756216142; bh=xkmVAjN+vkVTiyrNUpM7dZgjvNWAWnBI3PRoNu3Zwaw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Fqvm1kNv53I01vNdLXW4B7G21Rz4eclTAS+n8ymW+Um/KLGy+Qc8VKlc1ftgYwzXK /1ioj4C2d2FxlJ/3eM1rQQ6wRnKsLXi2/Dll3yf0Na6u8OGEmnykTSGW7xjGASoOfp oYDIunkAGeyy3jeNrhETiM8wGU+4BItlVS07oDwg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ma Ke , Jens Axboe Subject: [PATCH 5.15 268/644] sunvdc: Balance device refcount in vdc_port_mpgroup_check Date: Tue, 26 Aug 2025 13:05:59 +0200 Message-ID: <20250826110953.013726536@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110946.507083938@linuxfoundation.org> References: <20250826110946.507083938@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 5.15-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 @@ -948,8 +948,10 @@ 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; }