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| author | Ondrej Jirman <megous@megous.com> | 2019-04-06 01:30:48 +0200 |
|---|---|---|
| committer | Maxime Ripard <maxime.ripard@bootlin.com> | 2019-04-08 10:30:23 +0200 |
| commit | 1a07a94b47b1f528f39c3e6187b5eaf02efe44ea (patch) | |
| tree | ae77778c19997da18e07e4e44e51e8b4749614f6 /drivers/gpu/drm | |
| parent | b85d00bfef2a62180d9ae74ecc95befe37686836 (diff) | |
| download | linux-1a07a94b47b1f528f39c3e6187b5eaf02efe44ea.tar.gz linux-1a07a94b47b1f528f39c3e6187b5eaf02efe44ea.tar.bz2 linux-1a07a94b47b1f528f39c3e6187b5eaf02efe44ea.zip | |
drm/sun4i: tcon top: Fix NULL/invalid pointer dereference in sun8i_tcon_top_un/bind
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>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190405233048.3823-1-megous@megous.com
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/sun4i/sun8i_tcon_top.c | 5 |
1 files changed, 3 insertions, 2 deletions
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); |