[PATCH][next] drm/mediatek: avoid dereferencing a null hdmi_phy on an error message

From: Colin King
Date: Mon Dec 07 2020 - 10:10:46 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Currently there is a null pointer check for hdmi_phy that implies it
may be null, however a dev_err messages dereferences this potential null
pointer. Avoid a null pointer dereference by only emitting the dev_err
message if hdmi_phy is non-null. It is a moot point if the error message
needs to be printed at all, but since this is a relatively new piece of
code it may be useful to keep the message in for the moment in case there
are unforseen errors that need to be reported.

Addresses-Coverity: ("Dereference after null check")
Fixes: be28b6507c46 ("drm/mediatek: separate hdmi phy to different file")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/phy/mediatek/phy-mtk-hdmi.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-hdmi.c b/drivers/phy/mediatek/phy-mtk-hdmi.c
index c5c61f5a9ea0..5184054783c7 100644
--- a/drivers/phy/mediatek/phy-mtk-hdmi.c
+++ b/drivers/phy/mediatek/phy-mtk-hdmi.c
@@ -84,8 +84,9 @@ mtk_hdmi_phy_dev_get_ops(const struct mtk_hdmi_phy *hdmi_phy)
hdmi_phy->conf->hdmi_phy_disable_tmds)
return &mtk_hdmi_phy_dev_ops;

- dev_err(hdmi_phy->dev, "Failed to get dev ops of phy\n");
- return NULL;
+ if (hdmi_phy)
+ dev_err(hdmi_phy->dev, "Failed to get dev ops of phy\n");
+ return NULL;
}

static void mtk_hdmi_phy_clk_get_data(struct mtk_hdmi_phy *hdmi_phy,
--
2.29.2