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| author | Ming Lei <ming.lei@redhat.com> | 2022-12-13 15:16:27 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-18 09:26:05 +0100 |
| commit | bea54ce061c8ff28ce7727f3a048f6ffd9267e0f (patch) | |
| tree | c5a91231b65164183a6969ca393b09d33b1a5ab5 | |
| parent | c23105673228c349739e958fa33955ed8faddcaf (diff) | |
| download | linux-stable-bea54ce061c8ff28ce7727f3a048f6ffd9267e0f.tar.gz linux-stable-bea54ce061c8ff28ce7727f3a048f6ffd9267e0f.tar.bz2 linux-stable-bea54ce061c8ff28ce7727f3a048f6ffd9267e0f.zip | |
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>
| -rw-r--r-- | block/partition-generic.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/block/partition-generic.c b/block/partition-generic.c index db57cced9b98..68bd04d044b9 100644 --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -270,6 +270,7 @@ 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; @@ -283,6 +284,11 @@ void delete_partition(struct gendisk *disk, int partno) kobject_put(part->holder_dir); device_del(part_to_dev(part)); + bdev = bdget(part_devt(part)); + if (bdev) { + remove_inode_hash(bdev->bd_inode); + bdput(bdev); + } hd_struct_kill(part); } |