btrfs: qgroup: fix qgroup prealloc rsv leak in subvolume operations
概要
btrfs: qgroup: fix qgroup prealloc rsv leak in subvolume operations
原文の説明
取得元が公開している説明をそのまま載せています (多くは英語)。
In the Linux kernel, the following vulnerability has been resolved:
btrfs: qgroup: fix qgroup prealloc rsv leak in subvolume operations
Create subvolume, create snapshot and delete subvolume all use
btrfs_subvolume_reserve_metadata() to reserve metadata for the changes
done to the parent subvolume's fs tree, which cannot be mediated in the
normal way via start_transaction. When quota groups (squota or qgroups)
are enabled, this reserves qgroup metadata of type PREALLOC. Once the
operation is associated to a transaction, we convert PREALLOC to
PERTRANS, which gets cleared in bulk at the end of the transaction.
However, the error paths of these three operations were not implementing
this lifecycle correctly. They unconditionally converted the PREALLOC to
PERTRANS in a generic cleanup step regardless of errors or whether the
operation was fully associated to a transaction or not. This resulted in
error paths occasionally converting this rsv to PERTRANS without calling
record_root_in_trans successfully, which meant that unless that root got
recorded in the transaction by some other thread, the end of the
transaction would not free that root's PERTRANS, leaking it. Ultimately,
this resulted in hitting a WARN in CONFIG_BTRFS_DEBUG builds at unmount
for the leaked reservation.
The fix is to ensure that every qgroup PREALLOC reservation observes the
following properties:
- any failure before record_root_in_trans is called successfully
results in freeing the PREALLOC reservat…
影響パッケージ
ディストリビューション別の修正状況
各ディストリビューションが公開している、この CVE の修正パッケージ
- Debian DEBIAN-CVE-2024-35956 linux
- Ubuntu UBUNTU-CVE-2024-35956 linux-hwe-edge
参照URL
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web lists.debian.org