On Tue, Apr 21, 2020 at 10:54:11AM +0800, Xiyu Yang wrote: > btrfs_remove_block_group() invokes btrfs_lookup_block_group(), which > returns a local reference of the blcok group that contains the given > bytenr to "block_group" with increased refcount. > > When btrfs_remove_block_group() returns, "block_group" becomes invalid, > so the refcount should be decreased to keep refcount balanced. > > The reference counting issue happens in several exception handling paths > of btrfs_remove_block_group(). When those error scenarios occur such as > btrfs_alloc_path() returns NULL, the function forgets to decrease its > refcnt increased by btrfs_lookup_block_group() and will cause a refcnt > leak. > > Fix this issue by jumping to "out_put_group" label and calling > btrfs_put_block_group() when those error scenarios occur. > > Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> > Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx> Added to misc-next, thanks.
