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 V2 1/4] zram: fix race between zram_reset_device() and disksize_store()
Date: Wed, 20 Oct 2021 09:55:45 +0800 [thread overview]
Message-ID: <20211020015548.2374568-2-ming.lei@redhat.com> (raw)
In-Reply-To: <20211020015548.2374568-1-ming.lei@redhat.com>
When the ->init_lock is released in zram_reset_device(), disksize_store()
can come in and try to allocate meta, but zram_reset_device() is freeing
free meta, so cause races.
Link: https://lore.kernel.org/linux-block/20210927163805.808907-1-mcgrof@kernel.org/T/#mc617f865a3fa2778e40f317ddf48f6447c20c073
Reported-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/block/zram/zram_drv.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index a68297fb51a2..25d781dc5fef 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1704,12 +1704,13 @@ static void zram_reset_device(struct zram *zram)
set_capacity_and_notify(zram->disk, 0);
part_stat_set_all(zram->disk->part0, 0);
- up_write(&zram->init_lock);
/* I/O operation under all of CPU are done so let's free */
zram_meta_free(zram, disksize);
memset(&zram->stats, 0, sizeof(zram->stats));
zcomp_destroy(comp);
reset_bdev(zram);
+
+ up_write(&zram->init_lock);
}
static ssize_t disksize_store(struct device *dev,
--
2.31.1
next prev parent reply other threads:[~2021-10-20 1:56 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-20 1:55 [PATCH V2 0/4] zram: fix two races and one zram leak Ming Lei
2021-10-20 1:55 ` Ming Lei [this message]
2021-10-21 23:03 ` [PATCH V2 1/4] zram: fix race between zram_reset_device() and disksize_store() Luis Chamberlain
2021-10-20 1:55 ` [PATCH V2 2/4] zram: don't fail to remove zram during unloading module Ming Lei
2021-10-21 23:50 ` Luis Chamberlain
2021-10-22 0:38 ` Ming Lei
2021-10-20 1:55 ` [PATCH V2 3/4] zram: avoid race between zram_remove and disksize_store Ming Lei
2021-10-22 19:02 ` Luis Chamberlain
2021-10-20 1:55 ` [PATCH V2 4/4] zram: replace fsync_bdev with sync_blockdev Ming Lei
2021-10-22 19:06 ` Luis Chamberlain
2021-10-20 21:40 ` [PATCH V2 0/4] zram: fix two races and one zram leak Minchan Kim
2021-10-21 17:39 ` Luis Chamberlain
2021-10-21 17:46 ` Luis Chamberlain
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