From: Luiz Sampaio <sampaio.ime@xxxxxxxxx> [ Upstream commit 4daa9ff89ef27be43c15995412d6aee393a78200 ] Check if the pointer lcd->ops->init_display exists before dereferencing it. If a driver called charlcd_init() without defining the ops, this would return segmentation fault, as happened to me when implementing a charlcd driver. Checking the pointer before dereferencing protects from segmentation fault. Signed-off-by: Luiz Sampaio <sampaio.ime@xxxxxxxxx> Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/auxdisplay/charlcd.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c index 304accde365c8..6c010d4efa4ae 100644 --- a/drivers/auxdisplay/charlcd.c +++ b/drivers/auxdisplay/charlcd.c @@ -578,6 +578,9 @@ static int charlcd_init(struct charlcd *lcd) * Since charlcd_init_display() needs to write data, we have to * enable mark the LCD initialized just before. */ + if (WARN_ON(!lcd->ops->init_display)) + return -EINVAL; + ret = lcd->ops->init_display(lcd); if (ret) return ret; -- 2.34.1
