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From: Christoph Hellwig <hch@lst.de>
To: Tong Zhang <ztong0001@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>, Keith Busch <kbusch@kernel.org>,
	Jens Axboe <axboe@fb.com>, Sagi Grimberg <sagi@grimberg.me>,
	linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] nvme: fix use-after-free during booting
Date: Wed, 23 Sep 2020 07:57:25 +0200	[thread overview]
Message-ID: <20200923055725.GA15442@lst.de> (raw)
In-Reply-To: <61E8905E-E3FE-46EB-8283-9B35B4F069E1@gmail.com>

I suspect the patch below might be better.  Can you send me a full dmesg
with this one applied?  Preferably on top of Jens' for-next branch?


diff --git a/block/genhd.c b/block/genhd.c
index 9d060e79eb31d8..ef2784c69d59ee 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -832,7 +832,9 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk,
 	 * Take an extra ref on queue which will be put on disk_release()
 	 * so that it sticks around as long as @disk is there.
 	 */
-	WARN_ON_ONCE(!blk_get_queue(disk->queue));
+	WARN_ON_ONCE(blk_queue_dying(disk->queue));
+	__blk_get_queue(disk->queue);
+	disk->flags |= GENHD_FL_QUEUE_REF;
 
 	disk_add_events(disk);
 	blk_integrity_add(disk);
@@ -1564,7 +1566,7 @@ static void disk_release(struct device *dev)
 	kfree(disk->random);
 	disk_replace_part_tbl(disk, NULL);
 	hd_free_part(&disk->part0);
-	if (disk->queue)
+	if (disk->flags & GENHD_FL_QUEUE_REF)
 		blk_put_queue(disk->queue);
 	kfree(disk);
 }
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 1c97cf84f011a7..822a619924e3b5 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -133,6 +133,7 @@ struct hd_struct {
 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE	0x0100
 #define GENHD_FL_NO_PART_SCAN			0x0200
 #define GENHD_FL_HIDDEN				0x0400
+#define GENHD_FL_QUEUE_REF			0x0800
 
 enum {
 	DISK_EVENT_MEDIA_CHANGE			= 1 << 0, /* media changed */


  parent reply	other threads:[~2020-09-23  5:57 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-16 15:36 [PATCH] nvme: fix use-after-free during booting Tong Zhang
2020-09-17  8:26 ` Christoph Hellwig
2020-09-17 15:24   ` Tong Zhang
2020-09-17 15:26     ` Christoph Hellwig
2020-09-22 13:59 ` Christoph Hellwig
2020-09-22 15:40   ` Tong Zhang
     [not found]   ` <CAA5qM4BPKZaqH0SHS3zCO7oz=f3Ow_zB2fqtJYUrbbFBNbWsNQ@mail.gmail.com>
     [not found]     ` <20200922164154.GA1894@lst.de>
2020-09-22 20:34       ` Tong Zhang
2020-09-23  5:06         ` Christoph Hellwig
2020-09-23 16:40           ` Tong Zhang
2020-09-23  5:57         ` Christoph Hellwig [this message]
2020-09-23 16:32           ` Tong Zhang

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