[PATCH v3] mm/migrate_device: fix pgtable leak in migrate_vma_insert_huge_pmd_page
From: Sunny Patel
Date: Fri May 01 2026 - 07:51:40 EST
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.
Signed-off-by: Sunny Patel <nueralspacetech@xxxxxxxxx>
---
Changes in v3:
- Added free_abort label as suggested to release the pgtable
in error path.
- v2 had the pte_free() call in both error paths, this
version has a single goto target for both paths to avoid code duplication.
mm/migrate_device.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index fbfe5715f635..0360b410067b 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -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;
--
2.43.0