The patch titled
Subject: mm/vmalloc.c: vmap(): don't allow invalid pages
has been added to the -mm tree. Its filename is
vmap-dont-allow-invalid-pages.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/vmap-dont-allow-invalid-pages.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/vmap-dont-allow-invalid-pages.patch
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------------------------------------------------------
From: Yury Norov <yury.norov@xxxxxxxxx>
Subject: mm/vmalloc.c: vmap(): don't allow invalid pages
vmap() takes struct page *pages as one of arguments, and user may provide
an invalid pointer which would lead to data abort at address translation
later.
Currently, kernel checks the pages against NULL. In my case, however, the
address was not NULL, and was big enough so that the hardware generated
Address Size Abort on arm64.
Interestingly, this abort happens even if copy_from_kernel_nofault() is
used, which is quite inconvenient for debugging purposes.
This patch adds a pfn_valid() check into vmap() path, so that invalid
mapping will not be created.
Link: https://lkml.kernel.org/r/20220119012109.551931-1-yury.norov@xxxxxxxxx
Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
Suggested-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Ding Tianhong <dingtianhong@xxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Alexey Klimov <aklimov@xxxxxxxxxx>
Cc: Uladzislau Rezki <urezki@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 2 ++
1 file changed, 2 insertions(+)
--- a/mm/vmalloc.c~vmap-dont-allow-invalid-pages
+++ a/mm/vmalloc.c
@@ -479,6 +479,8 @@ static int vmap_pages_pte_range(pmd_t *p
return -EBUSY;
if (WARN_ON(!page))
return -ENOMEM;
+ if (WARN_ON(!pfn_valid(page_to_pfn(page))))
+ return -EINVAL;
set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
(*nr)++;
} while (pte++, addr += PAGE_SIZE, addr != end);
_
Patches currently in -mm which might be from yury.norov@xxxxxxxxx are
vmap-dont-allow-invalid-pages.patch
