Thread (2 messages) 2 messages, 2 authors, 2022-08-03
STALE1395d

[PATCH -next] rtc: synqmp: uninitialized variable error

From: Sebin Sebastian <hidden>
Date: 2022-08-03 01:31:37
Also in: linux-arm-kernel, lkml
Subsystem: real time clock (rtc) subsystem, the rest · Maintainers: Alexandre Belloni, Linus Torvalds

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
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