On 31 July 2015 at 21:03, Kees Cook <[email protected]> wrote: > On Fri, Jul 31, 2015 at 2:13 AM, Tomeu Vizoso <[email protected]> wrote: >> On 25 July 2015 at 01:20, Kees Cook <[email protected]> wrote: >>> Many callers either use NULL or const strings for the third argument of >>> clk_register_clkdev. For those that do not, this is a risk for format >>> strings being accidentally processed (for example in device names). This >>> adds the missing "%s" arguments to make sure format strings will not leak >>> into the clkdev. >>> >>> Signed-off-by: Kees Cook <[email protected]> >>> --- >> >> [...] >> >>> diff --git a/drivers/clk/tegra/clk.c b/drivers/clk/tegra/clk.c >>> index 41cd87c67be6..97d9fb7e89ad 100644 >>> --- a/drivers/clk/tegra/clk.c >>> +++ b/drivers/clk/tegra/clk.c >>> @@ -296,7 +296,7 @@ void __init tegra_register_devclks(struct tegra_devclk >>> *dev_clks, int num) >>> >>> for (i = 0; i < num; i++, dev_clks++) >>> clk_register_clkdev(clks[dev_clks->dt_id], dev_clks->con_id, >>> - dev_clks->dev_id); >>> + "%s", dev_clks->dev_id); >> >> This causes clocks to be registered with a dev_id string of "(null)", >> which is causing lookups that used to succeed before to fail. > > Oh yuck. Yeah, clk_register_clkdev handles a NULL argument differently > than other format-string style functions. Using > clk_register_clkdev(..., dev_clks->dev_id ? "%s" : NULL, > dev_clks->dev_id) seems really ugly to work around this, though. > Perhaps the format string capability should be removed?
Yeah, that sounds good to me. At least, I don't see as that good of an idea to save a few lines of code by making the API so prone to mistakes. Could this patch be removed from linux-next in the meantime? Thanks, Tomeu > -Kees > > -- > Kees Cook > Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
