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 A239A3ACA4B; Fri, 24 Apr 2026 11:42:15 +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=1777030935; cv=none; b=L1m1wcBd6i3afJqthFprMxOHKj/zLchVZPLQ4I/ZKlVPja9d0WKcC3FT2QIW0NLXRW9OIAfJf/EbCI8qrw9j2Hj+XgD1WnZeVzX0Jlzooo4vxEltNt4uJvhvJxa5PyoCOlSJZwLS0qEhFrlHoFg7gnDLxk/JoT/CnMHR1u9KOaw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777030935; c=relaxed/simple; bh=4W6W28oQ9tYxBvQu92r59YpXTkIqDtFU5bKJl2RfmB4=; h=Mime-Version:Content-Type:Date:Message-Id:From:Subject:Cc:To: References:In-Reply-To; b=OjcF+12HLxJ4//s//7h0OhBNmD4taRtEi2bpIqLCB0d/NyR4K0uTbpk24TJK+cUHW3tpxFOSLkfJKIVIQCS9p8uYWWsBb5ZW0KbNLjaa+tisuMYlzp7AMnz1abZHaLU/XOywZ6NK0rHj1YBjdjikS7pduQh/ybd8PF8G0ZO2cOo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WpFXVTpw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WpFXVTpw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 283B9C19425; Fri, 24 Apr 2026 11:42:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777030935; bh=4W6W28oQ9tYxBvQu92r59YpXTkIqDtFU5bKJl2RfmB4=; h=Date:From:Subject:Cc:To:References:In-Reply-To:From; b=WpFXVTpwYsAilpyRKcB2OkVSf3DerhzvCj9yDZIgXGtVye6lKjhyDQy3FdRT23OJw lxatoqec78Y0gYvbmaOHS7D7sBep9TnJvQkMQQ2Mkt70+UpWrUtEOD1EM1WcjY6TjB XS281/sZ63iVaVKiGPJKc7njUBqtueH5rf/FG3Cl7UEZVfqiB1xwlG7GglRPzyW4ru vYSN0vyaidYANRP7FzWSiHMkaebS7tIzpo2LFToWlRlYnKqwbQ1F4dtx+GxoBDunHP em1qYoELYpKOkCmuGbEnmglfg47fanVaxBpgE34rFnRVWZD3xCHNvgParchSYThJAh INwIaDkvOxdyg== Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Fri, 24 Apr 2026 13:42:12 +0200 Message-Id: From: "Danilo Krummrich" Subject: Re: [PATCH] driver core: faux: fix root device registration Cc: "Greg Kroah-Hartman" , "Rafael J . Wysocki" , , , To: "Johan Hovold" References: <20260424102231.2615557-1-johan@kernel.org> In-Reply-To: <20260424102231.2615557-1-johan@kernel.org> On Fri Apr 24, 2026 at 12:22 PM CEST, Johan Hovold wrote: > diff --git a/drivers/base/faux.c b/drivers/base/faux.c > index fb3e42f21362..402ed119dfdf 100644 > --- a/drivers/base/faux.c > +++ b/drivers/base/faux.c > @@ -133,6 +133,9 @@ struct faux_device *faux_device_create_with_groups(co= nst char *name, > struct device *dev; > int ret; > =20 > + if (IS_ERR_OR_NULL(faux_bus_root)) > + return NULL; As Greg mentioned, if this happens we already have a much bigger fundamenta= l problem earlier in the boot process. Anyway, I think this check only catches when root_device_register() fails, = but everything that comes after root_device_register() in faux_bus_init() still leaves us with a dangling pointer. > + > faux_obj =3D kzalloc_obj(*faux_obj); > if (!faux_obj) > return NULL; > @@ -234,17 +237,9 @@ int __init faux_bus_init(void) > { > int ret; > =20 > - faux_bus_root =3D kzalloc_obj(*faux_bus_root); > - if (!faux_bus_root) > - return -ENOMEM; > - > - dev_set_name(faux_bus_root, "faux"); > - > - ret =3D device_register(faux_bus_root); > - if (ret) { > - put_device(faux_bus_root); > - return ret; > - } > + faux_bus_root =3D root_device_register("faux"); > + if (IS_ERR(faux_bus_root)) > + return PTR_ERR(faux_bus_root); > =20 > ret =3D bus_register(&faux_bus_type); > if (ret) > @@ -260,6 +255,6 @@ int __init faux_bus_init(void) > bus_unregister(&faux_bus_type); > =20 > error_bus: > - device_unregister(faux_bus_root); > + root_device_unregister(faux_bus_root); > return ret; > } > --=20 > 2.53.0