imx274_read_reg() takes a u8 pointer ("reg") and casts it to pass it
to regmap_read(), which takes an unsigned int pointer. This results in
a corrupted stack and random crashes.
Fixes: 0985dd306f72 ("media: imx274: V4l2 driver for Sony imx274 CMOS sensor")
Cc: stable@xxxxxxxxxxxxxxx # 4.15.x
Signed-off-by: Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>
---
Notes!
I have no evidence of this bug showing up in the mainline driver. It
appeared on a modified version where imx274_read_reg() is used,
unmodified, in a different way than it does in mainline (passing a
pointer to a single u8 instead of a pointer to an element of a u8
array).
Also the bug is only present in versions v4.15 (where the driver was
added) to v4.19. The offending function is unused since commit
ca017467c78b ("media: imx274: add helper to read multibyte
registers"), merged in v4.20-rc1, thus master is not affected. I'm
sending this bugfix patch anyway for easier integration in the stable
branches. Later I plan to send a patch against master to entirely
remove the function. Or somebody might want to use this function
again, so better having a fixed version out anyway.
I'm not 100% sure this qualifies this commit for stable trees.
---
drivers/media/i2c/imx274.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
index e1b0395a657f..40c717f13eb8 100644
--- a/drivers/media/i2c/imx274.c
+++ b/drivers/media/i2c/imx274.c
@@ -619,16 +619,19 @@ static int imx274_write_table(struct stimx274 *priv, const struct reg_8 table[])
static inline int imx274_read_reg(struct stimx274 *priv, u16 addr, u8 *val)
{
+ unsigned int uint_val;
int err;
- err = regmap_read(priv->regmap, addr, (unsigned int *)val);
+ err = regmap_read(priv->regmap, addr, &uint_val);
if (err)
dev_err(&priv->client->dev,
"%s : i2c read failed, addr = %x\n", __func__, addr);
else
dev_dbg(&priv->client->dev,
"%s : addr 0x%x, val=0x%x\n", __func__,
- addr, *val);
+ addr, uint_val);
+
+ *val = uint_val;
return err;
}
--
2.17.1
