在 2024/8/29 01:44, Fedor Pchelkin 写道:
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>
Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
Thanks,
Qu
---
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 */
