Commit 2c6f81d5 authored by Sunny Patel's avatar Sunny Patel Committed by Andrew Morton
Browse files

mm/migrate_device: fix pgtable leak in migrate_vma_insert_huge_pmd_page 

When migrate_vma_insert_huge_pmd_page() jumps to unlock_abort due
to a PMD check failure, the pgtable allocated earlier via
pte_alloc_one() is never freed, causing a memory leak.

Added free_abort label to release the pgtable in error path.

Link: https://lore.kernel.org/20260501115122.23288-1-nueralspacetech@gmail.com


Fixes: a30b48bf ("mm/migrate_device: implement THP migration of zone device pages")
Signed-off-by: default avatarSunny Patel <nueralspacetech@gmail.com>
Acked-by: default avatarDavid Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: default avatarHuang Ying <ying.huang@linux.alibaba.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 09e7827e

mm/migrate_device.c

+3 −1
Original line number Diff line number Diff line
@@ -840,7 +840,7 @@ static int migrate_vma_insert_huge_pmd_page(struct migrate_vma *migrate, 
	} else {

		if (folio_is_zone_device(folio) &&

		    !folio_is_device_coherent(folio)) {

			goto abort;

			goto free_abort;

		}

		entry = folio_mk_pmd(folio, vma->vm_page_prot);

		if (vma->vm_flags & VM_WRITE)
@@ -893,6 +893,8 @@ static int migrate_vma_insert_huge_pmd_page(struct migrate_vma *migrate, 


unlock_abort:

	spin_unlock(ptl);

free_abort:

	pte_free(vma->vm_mm, pgtable);

abort:

	for (i = 0; i < HPAGE_PMD_NR; i++)

		src[i] &= ~MIGRATE_PFN_MIGRATE;