This is a note to let you know that I've just added the patch titled m68k: q40: Fix info-leak in rtc_ioctl to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: m68k-q40-fix-info-leak-in-rtc_ioctl.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 9c50c04d8d3a0d15b759957984241ad6cca30196 Author: Fuqian Huang <huangfq.daxian@xxxxxxxxx> Date: Fri Sep 27 20:15:44 2019 +0800 m68k: q40: Fix info-leak in rtc_ioctl [ 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> diff --git a/arch/m68k/q40/config.c b/arch/m68k/q40/config.c index e63eb5f069995..f31890078197e 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;