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> --- arch/m68k/q40/config.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/m68k/q40/config.c b/arch/m68k/q40/config.c index e63eb5f06999..f31890078197 100644 --- 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; -- 2.11.0