From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH] drm: sun4i: Fix NULL/invalid pointer dereference in sun8i_tcon_top_un/bind Date: Mon, 8 Apr 2019 10:31:10 +0200 Message-ID: <20190408083110.iy3auc7ggindifbf@flea> References: <20190405233048.3823-1-megous@megous.com> Reply-To: maxime.ripard-LDxbnhwyfcJBDgjK7y7TUQ@public.gmane.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="5xzbmyv2nly3kyer" Return-path: Sender: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org Content-Disposition: inline In-Reply-To: <20190405233048.3823-1-megous-5qf/QAjKc83QT0dZR+AlfA@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: megous-5qf/QAjKc83QT0dZR+AlfA@public.gmane.org Cc: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, David Airlie , Daniel Vetter , Chen-Yu Tsai , "open list:DRM DRIVERS FOR ALLWINNER A10" , "moderated list:ARM/Allwinner sunXi SoC support" , open list List-Id: dri-devel@lists.freedesktop.org --5xzbmyv2nly3kyer Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline On Sat, Apr 06, 2019 at 01:30:48AM +0200, megous-5qf/QAjKc83QT0dZR+AlfA@public.gmane.org wrote: > From: Ondrej Jirman > > There are two problems here: > > 1. Not all clk_data->hws[] need to be initialized, depending on various > configured quirks. This leads to NULL ptr deref in > clk_hw_unregister_gate() in sun8i_tcon_top_unbind() > 2. If there is error when registering the clk_data->hws[], > err_unregister_gates error path will try to unregister > IS_ERR()=true (invalid) pointer. > > For problem (1) I have this stack trace: > > Unable to handle kernel NULL pointer dereference at virtual > address 0000000000000008 > Call trace: > clk_hw_unregister+0x8/0x18 > clk_hw_unregister_gate+0x14/0x28 > sun8i_tcon_top_unbind+0x2c/0x60 > component_unbind.isra.4+0x2c/0x50 > component_bind_all+0x1d4/0x230 > sun4i_drv_bind+0xc4/0x1a0 > try_to_bring_up_master+0x164/0x1c0 > __component_add+0xa0/0x168 > component_add+0x10/0x18 > sun8i_dw_hdmi_probe+0x18/0x20 > platform_drv_probe+0x3c/0x70 > really_probe+0xcc/0x278 > driver_probe_device+0x34/0xa8 > > Problem (2) was identified by head scratching. > > Signed-off-by: Ondrej Jirman Changed the prefix to drm/sun4i: tcon top: and applied Thanks! Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --5xzbmyv2nly3kyer--