The quilt patch titled Subject: mm/gup: memfd: stop leaking pinned pages in low memory conditions has been removed from the -mm tree. Its filename was mm-gup-memfd-stop-leaking-pinned-pages-in-low-memory-conditions.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: John Hubbard <jhubbard@xxxxxxxxxx> Subject: mm/gup: memfd: stop leaking pinned pages in low memory conditions Date: Thu, 17 Oct 2024 18:17:11 -0700 If check_and_migrate_movable_pages() fails, typically with -ENOMEM, then memfd_pin_folios() will leave pages pinned. Those are leaked forever, and are visible to user space as a memory leak. Fix this by unpinning the folios that try_grab_folio(FOLL_PIN) has pinned, in such error cases. Link: https://lkml.kernel.org/r/20241018011711.183642-3-jhubbard@xxxxxxxxxx Fixes: 89c1905d9c14 ("mm/gup: introduce memfd_pin_folios() for pinning memfd folios") Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx> Suggested-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Alistair Popple <apopple@xxxxxxxxxx> Cc: Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Dave Airlie <airlied@xxxxxxxxxx> Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Peter Xu <peterx@xxxxxxxxxx> Cc: Dongwon Kim <dongwon.kim@xxxxxxxxx> Cc: Junxiao Chang <junxiao.chang@xxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx> Cc: Shigeru Yoshida <syoshida@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/gup.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/mm/gup.c~mm-gup-memfd-stop-leaking-pinned-pages-in-low-memory-conditions +++ a/mm/gup.c @@ -3724,12 +3724,10 @@ long memfd_pin_folios(struct file *memfd ret = check_and_migrate_movable_folios(nr_folios, folios); } while (ret == -EAGAIN); - memalloc_pin_restore(flags); - return ret ? ret : nr_folios; err: memalloc_pin_restore(flags); - unpin_folios(folios, nr_folios); - - return ret; + if (ret) + unpin_folios(folios, nr_folios); + return ret ? ret : nr_folios; } EXPORT_SYMBOL_GPL(memfd_pin_folios); _ Patches currently in -mm which might be from jhubbard@xxxxxxxxxx are kaslr-rename-physmem_end-and-physmem_end-to-direct_map_physmem_end.patch