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| author | Li Lingfeng <lilingfeng3@huawei.com> | 2023-11-07 11:34:35 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-11-07 16:14:57 +0100 |
| commit | 327462725b0f759f093788dfbcb2f1fd132f956b (patch) | |
| tree | ad6437b4535a62a854f869c0050eea1491b2b617 /drivers/block/nbd.c | |
| parent | Merge tag 'rtc-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni... (diff) | |
| download | linux-327462725b0f759f093788dfbcb2f1fd132f956b.tar.xz linux-327462725b0f759f093788dfbcb2f1fd132f956b.zip | |
nbd: fix uaf in nbd_open
Commit 4af5f2e03013 ("nbd: use blk_mq_alloc_disk and
blk_cleanup_disk") cleans up disk by blk_cleanup_disk() and it won't set
disk->private_data as NULL as before. UAF may be triggered in nbd_open()
if someone tries to open nbd device right after nbd_put() since nbd has
been free in nbd_dev_remove().
Fix this by implementing ->free_disk and free private data in it.
Fixes: 4af5f2e03013 ("nbd: use blk_mq_alloc_disk and blk_cleanup_disk")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20231107103435.2074904-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/nbd.c')
| -rw-r--r-- | drivers/block/nbd.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 800f131222fc..855fdf5c3b4e 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -250,7 +250,6 @@ static void nbd_dev_remove(struct nbd_device *nbd) struct gendisk *disk = nbd->disk; del_gendisk(disk); - put_disk(disk); blk_mq_free_tag_set(&nbd->tag_set); /* @@ -261,7 +260,7 @@ static void nbd_dev_remove(struct nbd_device *nbd) idr_remove(&nbd_index_idr, nbd->index); mutex_unlock(&nbd_index_mutex); destroy_workqueue(nbd->recv_workq); - kfree(nbd); + put_disk(disk); } static void nbd_dev_remove_work(struct work_struct *work) @@ -1608,6 +1607,13 @@ static void nbd_release(struct gendisk *disk) nbd_put(nbd); } +static void nbd_free_disk(struct gendisk *disk) +{ + struct nbd_device *nbd = disk->private_data; + + kfree(nbd); +} + static const struct block_device_operations nbd_fops = { .owner = THIS_MODULE, @@ -1615,6 +1621,7 @@ static const struct block_device_operations nbd_fops = .release = nbd_release, .ioctl = nbd_ioctl, .compat_ioctl = nbd_ioctl, + .free_disk = nbd_free_disk, }; #if IS_ENABLED(CONFIG_DEBUG_FS) |