On 9/22/23 11:49, Kees Cook wrote:
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>
Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Thanks
--
Gustavo
---
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);
