Commit 617787f1 authored by Yu Kuai's avatar Yu Kuai Committed by Song Liu
Browse files

md: use READ_ONCE/WRITE_ONCE for 'suspend_lo' and 'suspend_hi' 



Protect 'suspend_lo' and 'suspend_hi' with READ_ONCE/WRITE_ONCE to prevent
reading abnormal values.

Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Signed-off-by: default avatarSong Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-2-yukuai1@huaweicloud.com
parent 9e55a22f

drivers/md/md.c

+9 −7
Original line number Diff line number Diff line
@@ -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;

}
@@ -5179,7 +5179,8 @@ __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
@@ -5199,7 +5200,7 @@ 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);
@@ -5211,7 +5212,8 @@ __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
@@ -5231,7 +5233,7 @@ 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);