[PATCH] drm/gma500: fix potential NULL pointer dereference dereference

From: Gustavo A. R. Silva
Date: Fri Aug 11 2017 - 21:55:29 EST


NULL check at line 528: if (!sender || !data_out || !len_out) {, implies
that pointer _sender_ might be NULL.

Move pointer _sender_ dereference after NULL check in order to avoid a
potential NULL pointer dereference.

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/gma500/mdfld_dsi_pkg_sender.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/gma500/mdfld_dsi_pkg_sender.c b/drivers/gpu/drm/gma500/mdfld_dsi_pkg_sender.c
index 1616af2..c50534c 100644
--- a/drivers/gpu/drm/gma500/mdfld_dsi_pkg_sender.c
+++ b/drivers/gpu/drm/gma500/mdfld_dsi_pkg_sender.c
@@ -520,7 +520,7 @@ static int __read_panel_data(struct mdfld_dsi_pkg_sender *sender, u8 data_type,
u8 *data, u16 len, u32 *data_out, u16 len_out, bool hs)
{
unsigned long flags;
- struct drm_device *dev = sender->dev;
+ struct drm_device *dev;
int i;
u32 gen_data_reg;
int retry = MDFLD_DSI_READ_MAX_COUNT;
@@ -530,6 +530,8 @@ static int __read_panel_data(struct mdfld_dsi_pkg_sender *sender, u8 data_type,
return -EINVAL;
}

+ dev = sender->dev;
+
/**
* do reading.
* 0) send out generic read request
--
2.5.0