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? -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/
