From: Fuqian Huang huangfq.daxian@gmail.com
[ 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@gmail.com Link: https://lore.kernel.org/r/20190927121544.7650-1-huangfq.daxian@gmail.com Signed-off-by: Geert Uytterhoeven geert@linux-m68k.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 e90fe903613ea..4e5f04d333188 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;