[PATCH] media: v4l: Fix dereference before NULL check
From: Chandra Mohan Sundar <hidden>
Date: 2025-08-18 09:32:08
Also in:
linux-kernel-mentees, linux-media
Subsystem:
media drivers for stm32 - csi, media input infrastructure (v4l/dvb), the rest · Maintainers:
Alain Volmat, Mauro Carvalho Chehab, Linus Torvalds
In 'stm32_csi_start', 'csidev->s_subdev' is dereferenced directly while
assigning a value to the 'src_pad'. However the same value is being
checked against NULL at a later point of time indicating that there
are chances that the value can be NULL.
Move the dereference after the NULL check.
Fixes: e7bad98c205d1 ("media: v4l: Convert the users of v4l2_get_link_freq to call it on a pad")
Signed-off-by: Chandra Mohan Sundar <redacted>
---
drivers/media/platform/st/stm32/stm32-csi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/media/platform/st/stm32/stm32-csi.c b/drivers/media/platform/st/stm32/stm32-csi.c
index b69048144cc1..fd2b6dfbd44c 100644
--- a/drivers/media/platform/st/stm32/stm32-csi.c
+++ b/drivers/media/platform/st/stm32/stm32-csi.c@@ -443,8 +443,7 @@ static void stm32_csi_phy_reg_write(struct stm32_csi_dev *csidev, static int stm32_csi_start(struct stm32_csi_dev *csidev, struct v4l2_subdev_state *state) { - struct media_pad *src_pad = - &csidev->s_subdev->entity.pads[csidev->s_subdev_pad_nb]; + struct media_pad *src_pad; const struct stm32_csi_mbps_phy_reg *phy_regs = NULL; struct v4l2_mbus_framefmt *sink_fmt; const struct stm32_csi_fmts *fmt;
@@ -466,6 +465,7 @@ static int stm32_csi_start(struct stm32_csi_dev *csidev, if (!csidev->s_subdev) return -EIO; + src_pad = &csidev->s_subdev->entity.pads[csidev->s_subdev_pad_nb]; link_freq = v4l2_get_link_freq(src_pad, fmt->bpp, 2 * csidev->num_lanes); if (link_freq < 0)
--
2.43.0