From: Yu Kuai <yukuai3@xxxxxxxxxx>
Because reading 'suspend_lo' and 'suspend_hi' from md_handle_request()
is not protected, use READ_ONCE/WRITE_ONCE to prevent reading abnormal
value.
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
drivers/md/md.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 46badd13a687..9d8dff9d923c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -359,11 +359,11 @@ static bool is_suspended(struct mddev *mddev, struct bio *bio)
return true;
if (bio_data_dir(bio) != WRITE)
return false;
- if (mddev->suspend_lo >= mddev->suspend_hi)
+ if (READ_ONCE(mddev->suspend_lo) >= READ_ONCE(mddev->suspend_hi))
return false;
- if (bio->bi_iter.bi_sector >= mddev->suspend_hi)
+ if (bio->bi_iter.bi_sector >= READ_ONCE(mddev->suspend_hi))
return false;
- if (bio_end_sector(bio) < mddev->suspend_lo)
+ if (bio_end_sector(bio) < READ_ONCE(mddev->suspend_lo))
return false;
return true;
}
@@ -5171,7 +5171,8 @@ __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
static ssize_t
suspend_lo_show(struct mddev *mddev, char *page)
{
- return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
+ return sprintf(page, "%llu\n",
+ (unsigned long long)READ_ONCE(mddev->suspend_lo));
}
static ssize_t
@@ -5191,7 +5192,7 @@ suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
return err;
mddev_suspend(mddev);
- mddev->suspend_lo = new;
+ WRITE_ONCE(mddev->suspend_lo, new);
mddev_resume(mddev);
mddev_unlock(mddev);
@@ -5203,7 +5204,8 @@ __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
static ssize_t
suspend_hi_show(struct mddev *mddev, char *page)
{
- return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
+ return sprintf(page, "%llu\n",
+ (unsigned long long)READ_ONCE(mddev->suspend_hi));
}
static ssize_t
@@ -5223,7 +5225,7 @@ suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
return err;
mddev_suspend(mddev);
- mddev->suspend_hi = new;
+ WRITE_ONCE(mddev->suspend_hi, new);
mddev_resume(mddev);
mddev_unlock(mddev);
--
2.39.2
--
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