Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct i2c_demux_pinctrl_priv. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Rosin <peda@xxxxxxxxxx> Cc: linux-i2c@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- drivers/i2c/muxes/i2c-demux-pinctrl.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/muxes/i2c-demux-pinctrl.c b/drivers/i2c/muxes/i2c-demux-pinctrl.c index a3a122fae71e..5e15d8777229 100644 --- a/drivers/i2c/muxes/i2c-demux-pinctrl.c +++ b/drivers/i2c/muxes/i2c-demux-pinctrl.c @@ -32,7 +32,7 @@ struct i2c_demux_pinctrl_priv { const char *bus_name; struct i2c_adapter cur_adap; struct i2c_algorithm algo; - struct i2c_demux_pinctrl_chan chan[]; + struct i2c_demux_pinctrl_chan chan[] __counted_by(num_chan); }; static int i2c_demux_master_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) @@ -226,6 +226,8 @@ static int i2c_demux_pinctrl_probe(struct platform_device *pdev) if (!priv || !props) return -ENOMEM; + priv->num_chan = num_chan; + err = of_property_read_string(np, "i2c-bus-name", &priv->bus_name); if (err) return err; @@ -248,8 +250,6 @@ static int i2c_demux_pinctrl_probe(struct platform_device *pdev) of_changeset_init(&priv->chan[i].chgset); of_changeset_update_property(&priv->chan[i].chgset, adap_np, &props[i]); } - - priv->num_chan = num_chan; priv->dev = &pdev->dev; platform_set_drvdata(pdev, priv); -- 2.34.1
