diff options
| author | Ming Lei <ming.lei@redhat.com> | 2022-12-05 21:27:39 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-08 11:23:59 +0100 |
| commit | 5f2f775605917aa5087ee5c6f3339da94c100679 (patch) | |
| tree | 380dc8811adb3e532a369e8061d4e0929f5166f0 /block | |
| parent | a82869ac52f3d9db4b2cf8fd41edc2dee7a75a61 (diff) | |
block: unhash blkdev part inode when the part is deleted
v5.11 changes the blkdev lookup mechanism completely since commit
22ae8ce8b892 ("block: simplify bdev/disk lookup in blkdev_get"),
and small part of the change is to unhash part bdev inode when
deleting partition. Turns out this kind of change does fix one
nasty issue in case of BLOCK_EXT_MAJOR:
1) when one partition is deleted & closed, disk_put_part() is always
called before bdput(bdev), see blkdev_put(); so the part's devt can
be freed & re-used before the inode is dropped
2) then new partition with same devt can be created just before the
inode in 1) is dropped, then the old inode/bdev structurein 1) is
re-used for this new partition, this way causes use-after-free and
kernel panic.
It isn't possible to backport the whole big patchset of "merge struct
block_device and struct hd_struct v4" for addressing this issue.
https://lore.kernel.org/linux-block/20201128161510.347752-1-hch@lst.de/
So fixes it by unhashing part bdev in delete_partition(), and this way
is actually aligned with v5.11+'s behavior.
Reported-by: Shiwei Cui <cuishw@inspur.com>
Tested-by: Shiwei Cui <cuishw@inspur.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/partitions/core.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/block/partitions/core.c b/block/partitions/core.c index a02e22411594..e3d61ec4a5a6 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -329,6 +329,7 @@ void delete_partition(struct hd_struct *part) struct gendisk *disk = part_to_disk(part); struct disk_part_tbl *ptbl = rcu_dereference_protected(disk->part_tbl, 1); + struct block_device *bdev; /* * ->part_tbl is referenced in this part's release handler, so @@ -346,6 +347,12 @@ void delete_partition(struct hd_struct *part) * "in-use" until we really free the gendisk. */ blk_invalidate_devt(part_devt(part)); + + bdev = bdget_part(part); + if (bdev) { + remove_inode_hash(bdev->bd_inode); + bdput(bdev); + } percpu_ref_kill(&part->ref); } |