From: Li Nan <linan122@xxxxxxxxxx>
There is no input check when echo md/safe_mode_delay in safe_delay_store().
And msec might also overflow when HZ < 1000 in safe_delay_show(), Fix it by
checking overflow in safe_delay_store() and use unsigned long conversion in
safe_delay_show().
Fixes: 72e02075a33f ("md: factor out parsing of fixed-point numbers")
Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
---
drivers/md/md.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8e344b4b3444..b2d69260b5b1 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3794,8 +3794,9 @@ int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
static ssize_t
safe_delay_show(struct mddev *mddev, char *page)
{
- int msec = (mddev->safemode_delay*1000)/HZ;
- return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
+ unsigned int msec = ((unsigned long)mddev->safemode_delay*1000)/HZ;
+
+ return sprintf(page, "%u.%03u\n", msec/1000, msec%1000);
}
static ssize_t
safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len)
@@ -3807,7 +3808,7 @@ safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len)
return -EINVAL;
}
- if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
+ if (strict_strtoul_scaled(cbuf, &msec, 3) < 0 || msec > UINT_MAX / HZ)
return -EINVAL;
if (msec == 0)
mddev->safemode_delay = 0;
--
2.31.1
