Re: [PATCH -next] rtc: synqmp: uninitialized variable error
From: Michal Simek <michal.simek@amd.com>
Date: 2022-08-03 05:47:04
Also in:
linux-arm-kernel, lkml
Hi, On 8/3/22 03:31, Sebin Sebastian wrote:
quoted hunk ↗ jump to hunk
fract_tick is uninitialized and can lead to uninitialized read which can result in any arbitrary value from previous computations. If the code flow doesnt execute the `if (fract_offset > (tick_mult / RTC_FR_MAX_TICKS)) { ` block, fract_tick is left uninitialized. Initializing with zero fixes the issue. Signed-off-by: Sebin Sebastian <redacted> --- drivers/rtc/rtc-zynqmp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c index 1dd389b891fe..c9b85c838ebe 100644 --- a/drivers/rtc/rtc-zynqmp.c +++ b/drivers/rtc/rtc-zynqmp.c@@ -203,7 +203,7 @@ static int xlnx_rtc_set_offset(struct device *dev, long offset) struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev); unsigned long long rtc_ppb = RTC_PPB; unsigned int tick_mult = do_div(rtc_ppb, xrtcdev->freq); - unsigned char fract_tick; + unsigned char fract_tick = 0; unsigned int calibval; short int max_tick; int fract_offset; --2.34.1
Alexandre already send the patch for it here. https://lore.kernel.org/r/20220727100018.3301470-1-alexandre.belloni@bootlin.com (local) Thanks, Michal