diff options
| author | Ming Lei <ming.lei@redhat.com> | 2022-12-13 15:16:03 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-19 12:24:16 +0100 |
| commit | a40c3c9ae58f39b007fc72f78bb6d57de28dd099 (patch) | |
| tree | 4e497b867b372f0e8f8b4dd5668cff330855501d /block | |
| parent | 176ba4c19d1bb153aa6baaa61d586e785b7d736c (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.
Backported from the following 5.10.y commit:
5f2f77560591 ("block: unhash blkdev part inode when the part is deleted")
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/partition-generic.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/block/partition-generic.c b/block/partition-generic.c index aee643ce13d1..e69452c1f5ad 100644 --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -272,6 +272,7 @@ void delete_partition(struct gendisk *disk, int partno) struct disk_part_tbl *ptbl = rcu_dereference_protected(disk->part_tbl, 1); struct hd_struct *part; + struct block_device *bdev; if (partno >= ptbl->len) return; @@ -292,6 +293,12 @@ void delete_partition(struct gendisk *disk, int partno) * "in-use" until we really free the gendisk. */ blk_invalidate_devt(part_devt(part)); + + bdev = bdget(part_devt(part)); + if (bdev) { + remove_inode_hash(bdev->bd_inode); + bdput(bdev); + } hd_struct_kill(part); } |