[PATCH v3 05/10] mm/vmalloc: reject an unaligned range in vmap_pages_pte_range()

[Hao Ge <hao.ge@linux.dev>]

commit a739e6b557af ("mm: vmalloc: WARN_ON if mapping size is not
PAGE_SIZE aligned") made vmap_pte_range() warn and bail out when the
size is not a multiple of PAGE_SIZE. Its loop only stops at
addr == end and otherwise steps over it and maps over whatever
follows the page table. vmap_pages_pte_range() has the same kind of
loop but was never given the check.

Add it there as a backstop.

Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Hao Ge <hao.ge@linux.dev>
---
 mm/vmalloc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d60b99b81ec9..c0f33392c6ad 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -557,6 +557,9 @@ static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr,
 	int err = 0;
 	pte_t *pte;
 
+	if (WARN_ON_ONCE(!PAGE_ALIGNED(end - addr)))
+		return -EINVAL;
+
 	/*
 	 * nr is a running index into the array which helps higher level
 	 * callers keep track of where we're up to.
-- 
2.25.1