On Wed, Aug 28, 2024 at 07:14:11PM +0300, Fedor Pchelkin wrote: > 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> This version looks even better, to me. Thanks for the catch and fix! Reviewed-by: Boris Burkov <boris@xxxxxx> > --- > 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 >
