+ mm-migrate_device-fix-pgtable-leak-in-migrate_vma_insert_huge_pmd_page.patch added to mm-hotfixes-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/migrate_device: fix pgtable leak in migrate_vma_insert_huge_pmd_page
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     mm-migrate_device-fix-pgtable-leak-in-migrate_vma_insert_huge_pmd_page.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-migrate_device-fix-pgtable-leak-in-migrate_vma_insert_huge_pmd_page.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Sunny Patel <nueralspacetech@gmail.com>
Subject: mm/migrate_device: fix pgtable leak in migrate_vma_insert_huge_pmd_page
Date: Fri, 1 May 2026 17:21:16 +0530

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: a30b48bf1b24 ("mm/migrate_device: implement THP migration of zone device pages")
Signed-off-by: Sunny Patel <nueralspacetech@gmail.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
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: "Huang, Ying" <ying.huang@linux.alibaba.com>
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: Andrew Morton <akpm@linux-foundation.org>
---

 mm/migrate_device.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/mm/migrate_device.c~mm-migrate_device-fix-pgtable-leak-in-migrate_vma_insert_huge_pmd_page
+++ a/mm/migrate_device.c
@@ -840,7 +840,7 @@ static int migrate_vma_insert_huge_pmd_p
 	} 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_p
 
 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;
_

Patches currently in -mm which might be from nueralspacetech@gmail.com are

mm-migrate_device-fix-spinlock-leak-in-migrate_vma_insert_huge_pmd_page.patch
mm-migrate_device-fix-pgtable-leak-in-migrate_vma_insert_huge_pmd_page.patch
mm-migrate_device-cleanup-up-pmd-checks-and-warnings.patch