On 11/17/21 11:38, Mina Almasry wrote:
Currently in the is_continue case in hugetlb_mcopy_atomic_pte(), if we bail out using "goto out_release_unlock;" in the cases where idx >= size, or !huge_pte_none(), the code will detect that new_pagecache_page == false, and so call restore_reserve_on_error(). In this case I see restore_reserve_on_error() delete the reservation, and the following call to remove_inode_hugepages() will increment h->resv_hugepages causing a 100% reproducible leak.
We should treat the is_continue case similar to adding a page into the pagecache and set new_pagecache_page to true, to indicate that there is no reservation to restore on the error path, and we need not call restore_reserve_on_error(). Rename new_pagecache_page to page_in_pagecache to make that clear.
Cc: Wei Xu weixugc@google.com
Cc: stable@vger.kernel.org
Fixes: c7b1850dfb41 ("hugetlb: don't pass page cache pages to restore_reserve_on_error") Signed-off-by: Mina Almasry almasrymina@google.com Reported-by: James Houghton jthoughton@google.com
Changes in v2:
- Renamed new_pagecache_page to page_in_pagecache
- Removed unnecessary comment after the name update.
- Cc: stable
Thanks for making the changes!
Reviewed-by: Mike Kravetz mike.kravetz@oracle.com