mm: don't skip arch_sync_kernel_mappings() in error paths

commit 3685024edd270f7c791f993157d65d3c928f3d6e upstream.

Fix callers that previously skipped calling arch_sync_kernel_mappings() if
an error occurred during a pgtable update.  The call is still required to
sync any pgtable updates that may have occurred prior to hitting the error
condition.

These are theoretical bugs discovered during code review.

Link: https://lkml.kernel.org/r/20250226121610.2401743-1-ryan.roberts@arm.com
Fixes: 2ba3e6947aed ("mm/vmalloc: track which page-table levels were modified")
Fixes: 0c95cba49255 ("mm: apply_to_pte_range warn and fail if a large pte is encountered")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christop Hellwig <hch@infradead.org>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/mm/memory.c b/mm/memory.c
index 4785aecca9a806eeb85c2e0063d6939433a57fbb..62fe3707ff92fa28ee33c3d02df800679cf35cd9 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2713,8 +2713,10 @@ static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr,
                next = pgd_addr_end(addr, end);
                if (pgd_none(*pgd) && !create)
                        continue;
-               if (WARN_ON_ONCE(pgd_leaf(*pgd)))
-                       return -EINVAL;
+               if (WARN_ON_ONCE(pgd_leaf(*pgd))) {
+                       err = -EINVAL;
+                       break;
+               }
                if (!pgd_none(*pgd) && WARN_ON_ONCE(pgd_bad(*pgd))) {
                        if (!create)
                                continue;

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 3cb1f59d1b53eaccc1350ffd3bbc6439c9c77c7f..840e25cab9344d18704f47755c028e71b50d6f93 100644 (file)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -556,13 +556,13 @@ static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end,
                        mask |= PGTBL_PGD_MODIFIED;
                err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask);
                if (err)
-                       return err;
+                       break;
        } while (pgd++, addr = next, addr != end);
 
        if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
                arch_sync_kernel_mappings(start, end);
 
-       return 0;
+       return err;
 }
 
 /*