diff options
| author | Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> | 2021-10-02 11:23:02 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-10-02 15:29:20 +0200 |
| commit | 06cc978d3ff226072780f74897800b33e78abb57 (patch) | |
| tree | f8a7767f98974d2bea074848be82708931e5795a /block/genhd.c | |
| parent | nbd: use shifts rather than multiplies (diff) | |
| download | linux-06cc978d3ff226072780f74897800b33e78abb57.tar.xz linux-06cc978d3ff226072780f74897800b33e78abb57.zip | |
block: genhd: fix double kfree() in __alloc_disk_node()
syzbot is reporting use-after-free read at bdev_free_inode() [1], for
kfree() from __alloc_disk_node() is called before bdev_free_inode()
(which is called after RCU grace period) reads bdev->bd_disk and calls
kfree(bdev->bd_disk).
Fix use-after-free read followed by double kfree() problem
by making sure that bdev->bd_disk is NULL when calling iput().
Link: https://syzkaller.appspot.com/bug?extid=8281086e8a6fbfbd952a [1]
Reported-by: syzbot <syzbot+8281086e8a6fbfbd952a@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/e6dd13c5-8db0-4392-6e78-a42ee5d2a1c4@i-love.sakura.ne.jp
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/genhd.c')
| -rw-r--r-- | block/genhd.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/block/genhd.c b/block/genhd.c index 7b6e5e1cf956..496e8458c357 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1268,6 +1268,7 @@ struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id, out_destroy_part_tbl: xa_destroy(&disk->part_tbl); + disk->part0->bd_disk = NULL; iput(disk->part0->bd_inode); out_free_bdi: bdi_put(disk->bdi); |