From: Fuqian Huang <huangfq.daxian@xxxxxxxxx> [ Upstream commit 7cf78b6b12fd5550545e4b73b35dca18bd46b44c ] 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> Link: https://lore.kernel.org/r/20190927121544.7650-1-huangfq.daxian@xxxxxxxxx Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 71c0867ecf20f..7fdf4e7799bcd 100644 --- a/arch/m68k/q40/config.c +++ b/arch/m68k/q40/config.c @@ -303,6 +303,7 @@ 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; -- 2.25.1
