From: Ming Lei <ming.lei@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, Luis Chamberlain <mcgrof@kernel.org>,
Minchan Kim <minchan@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, Ming Lei <ming.lei@redhat.com>
Subject: [PATCH V3 3/4] zram: avoid race between zram_remove and disksize_store
Date: Mon, 25 Oct 2021 10:54:25 +0800 [thread overview]
Message-ID: <20211025025426.2815424-4-ming.lei@redhat.com> (raw)
In-Reply-To: <20211025025426.2815424-1-ming.lei@redhat.com>
After resetting device in zram_remove(), disksize_store still may come and
allocate resources again before deleting gendisk, fix the race by resetting
zram after del_gendisk() returns. At that time, disksize_store can't come
any more.
Reported-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/block/zram/zram_drv.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 8883de7aa3d7..dba93b8ce511 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -2002,6 +2002,13 @@ static int zram_remove(struct zram *zram)
/* del_gendisk drains pending reset_store */
WARN_ON_ONCE(claimed && zram->claim);
+ /*
+ * disksize_store() may be called in between zram_reset_device()
+ * and del_gendisk(), so run the last reset to avoid leaking
+ * anything allocated with disksize_store()
+ */
+ zram_reset_device(zram);
+
blk_cleanup_disk(zram->disk);
kfree(zram);
return 0;
--
2.31.1
next prev parent reply other threads:[~2021-10-25 2:55 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-25 2:54 [PATCH V3 0/4] zram: fix two races and one zram leak Ming Lei
2021-10-25 2:54 ` [PATCH V3 1/4] zram: fix race between zram_reset_device() and disksize_store() Ming Lei
2021-10-25 2:54 ` [PATCH V3 2/4] zram: don't fail to remove zram during unloading module Ming Lei
2021-10-25 2:54 ` Ming Lei [this message]
2021-10-25 2:54 ` [PATCH V3 4/4] zram: replace fsync_bdev with sync_blockdev Ming Lei
2021-10-25 16:30 ` [PATCH V3 0/4] zram: fix two races and one zram leak Minchan Kim
2021-11-01 0:28 ` Ming Lei
2021-11-02 20:43 ` Jens Axboe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20211025025426.2815424-4-ming.lei@redhat.com \
--to=ming.lei@redhat.com \
--cc=axboe@kernel.dk \
--cc=gregkh@linuxfoundation.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mcgrof@kernel.org \
--cc=minchan@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).