| Message ID | 20190405233048.3823-1-megous@megous.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: sun4i: Fix NULL/invalid pointer dereference in sun8i_tcon_top_un/bind | expand |
On Sat, Apr 06, 2019 at 01:30:48AM +0200, megous@megous.com wrote: > From: Ondrej Jirman <megous@megous.com> > > 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 <megous@megous.com> Changed the prefix to drm/sun4i: tcon top: and applied Thanks! Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
diff --git a/drivers/gpu/drm/sun4i/sun8i_tcon_top.c b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c index fc36e0c10a37..b1e7c76e9c17 100644 --- a/drivers/gpu/drm/sun4i/sun8i_tcon_top.c +++ b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c @@ -227,7 +227,7 @@ static int sun8i_tcon_top_bind(struct device *dev, struct device *master, err_unregister_gates: for (i = 0; i < CLK_NUM; i++) - if (clk_data->hws[i]) + if (!IS_ERR_OR_NULL(clk_data->hws[i])) clk_hw_unregister_gate(clk_data->hws[i]); clk_disable_unprepare(tcon_top->bus); err_assert_reset: @@ -245,7 +245,8 @@ static void sun8i_tcon_top_unbind(struct device *dev, struct device *master, of_clk_del_provider(dev->of_node); for (i = 0; i < CLK_NUM; i++) - clk_hw_unregister_gate(clk_data->hws[i]); + if (clk_data->hws[i]) + clk_hw_unregister_gate(clk_data->hws[i]); clk_disable_unprepare(tcon_top->bus); reset_control_assert(tcon_top->rst);