| Message ID | e4e078ed-9342-48f4-80c5-28f0f7b711b0@stanley.mountain (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [next] drm/fsl-dcu: prevent error pointer dereference in fsl_dcu_load() | expand |
On Wed, 2024-10-23 at 11:35 +0300, Dan Carpenter wrote: > > The syscon_regmap_lookup_by_compatible() function returns -ENODEV if > there isn't a compatible for it or other error pointers on error. This > code only checks for -ENODEV instead of checking for other errors so it > could lead to an error pointer dereference inside the regmap_update_bits() > function. > > Fixes: ffcde9e44d3e ("drm: fsl-dcu: enable PIXCLK on LS1021A") > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> > --- > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c > index 91a48d774cf7..5997d9b4a431 100644 > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c > @@ -109,7 +109,9 @@ static int fsl_dcu_load(struct drm_device *dev, unsigned long flags) > return dev_err_probe(dev->dev, ret, "failed to initialize mode setting\n"); > > scfg = syscon_regmap_lookup_by_compatible("fsl,ls1021a-scfg"); > - if (PTR_ERR(scfg) != -ENODEV) { > + if (IS_ERR(scfg) && PTR_ERR(scfg) != -ENODEV) > + return dev_err_probe(dev->dev, PTR_ERR(scfg), "failed to find regmap\n"); > + if (!IS_ERR(scfg)) { > /* > * For simplicity, enable the PIXCLK unconditionally, > * resulting in increased power consumption. Disabling
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c index 91a48d774cf7..5997d9b4a431 100644 --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c @@ -109,7 +109,9 @@ static int fsl_dcu_load(struct drm_device *dev, unsigned long flags) return dev_err_probe(dev->dev, ret, "failed to initialize mode setting\n"); scfg = syscon_regmap_lookup_by_compatible("fsl,ls1021a-scfg"); - if (PTR_ERR(scfg) != -ENODEV) { + if (IS_ERR(scfg) && PTR_ERR(scfg) != -ENODEV) + return dev_err_probe(dev->dev, PTR_ERR(scfg), "failed to find regmap\n"); + if (!IS_ERR(scfg)) { /* * For simplicity, enable the PIXCLK unconditionally, * resulting in increased power consumption. Disabling
The syscon_regmap_lookup_by_compatible() function returns -ENODEV if there isn't a compatible for it or other error pointers on error. This code only checks for -ENODEV instead of checking for other errors so it could lead to an error pointer dereference inside the regmap_update_bits() function. Fixes: ffcde9e44d3e ("drm: fsl-dcu: enable PIXCLK on LS1021A") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> --- drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)