The local extent changeset is passed to clear_record_extent_bits() where it may have some additional memory dynamically allocated for ulist. When qgroup is disabled, the memory is leaked because in this case the changeset is not released upon __btrfs_qgroup_release_data() return. Since the recorded contents of the changeset are not used thereafter, just don't pass it. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Reported-by: syzbot+81670362c283f3dd889c@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://lore.kernel.org/lkml/000000000000aa8c0c060ade165e@xxxxxxxxxx Fixes: af0e2aab3b70 ("btrfs: qgroup: flush reservations during quota disable") Cc: stable@xxxxxxxxxxxxxxx # 6.10+ Signed-off-by: Fedor Pchelkin <pchelkin@xxxxxxxxx> --- v2: rework the fix as Qu Wenruo suggested - just don't pass unneeded changeset. Update the commit title and description accordingly. fs/btrfs/qgroup.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 5d57a285d59b..f6118c5f3c9f 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -4344,10 +4344,9 @@ static int __btrfs_qgroup_release_data(struct btrfs_inode *inode, int ret; if (btrfs_qgroup_mode(inode->root->fs_info) == BTRFS_QGROUP_MODE_DISABLED) { - extent_changeset_init(&changeset); return clear_record_extent_bits(&inode->io_tree, start, start + len - 1, - EXTENT_QGROUP_RESERVED, &changeset); + EXTENT_QGROUP_RESERVED, NULL); } /* In release case, we shouldn't have @reserved */ -- 2.39.2
