[PATCH] mdio-mux-gpio: Remove VLA usage
From: Kees Cook <hidden>
Date: 2018-05-29 22:59:08
Also in:
lkml
Subsystem:
ethernet phy library, networking drivers, the rest · Maintainers:
Andrew Lunn, Heiner Kallweit, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
In the quest to remove all stack VLA usage from the kernel[1], this allocates the values buffer during the callback instead of putting it on the stack. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Signed-off-by: Kees Cook <redacted> --- drivers/net/phy/mdio-mux-gpio.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/net/phy/mdio-mux-gpio.c b/drivers/net/phy/mdio-mux-gpio.c
index 082ffef0dec4..e99994f4ed50 100644
--- a/drivers/net/phy/mdio-mux-gpio.c
+++ b/drivers/net/phy/mdio-mux-gpio.c@@ -26,18 +26,23 @@ static int mdio_mux_gpio_switch_fn(int current_child, int desired_child, void *data) { struct mdio_mux_gpio_state *s = data; - int values[s->gpios->ndescs]; + int *values; unsigned int n; if (current_child == desired_child) return 0; + values = kmalloc_array(s->gpios->ndescs, sizeof(*values), GFP_KERNEL); + if (!values) + return -ENOMEM; + for (n = 0; n < s->gpios->ndescs; n++) values[n] = (desired_child >> n) & 1; gpiod_set_array_value_cansleep(s->gpios->ndescs, s->gpios->desc, values); + kfree(values); return 0; }
--
2.17.0
--
Kees Cook
Pixel Security