Hi Fuqian,
On Fri, Sep 27, 2019 at 2:15 PM Fuqian Huang <huangfq.daxian@xxxxxxxxx> wrote:
When the option is RTC_PLL_GET, pll will be copied to userland
via copy_to_user. pll is initialized using mach_get_rtc_pll indirect
call and mach_get_rtc_pll is only assigned with function
q40_get_rtc_pll in arch/m68k/q40/config.c.
In function q40_get_rtc_pll, the field pll_ctrl is not initialized.
This will leak uninitialized stack content to userland.
Fix this by zeroing the uninitialized field.
Signed-off-by: Fuqian Huang <huangfq.daxian@xxxxxxxxx>
Thanks for your patch!
--- a/arch/m68k/q40/config.c
+++ b/arch/m68k/q40/config.c
@@ -264,6 +264,7 @@ static int q40_get_rtc_pll(struct rtc_pll_info *pll)
{
int tmp = Q40_RTC_CTRL;
+ pll->pll_ctrl = 0;
pll->pll_value = tmp & Q40_RTC_PLL_MASK;
if (tmp & Q40_RTC_PLL_SIGN)
pll->pll_value = -pll->pll_value;
Nice catch!
Reviewed-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
i.e. will queue for v5.5.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
