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| author | Ryan Roberts <ryan.roberts@arm.com> | 2023-06-02 12:29:46 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-06-10 02:25:55 +0300 |
| commit | b3f78e74986546a6da5d28c24e627d95d17f79ec (patch) | |
| tree | 7ec12d72f26a0d6492db565b2997f8aa0dc28da9 /mm/vmalloc.c | |
| parent | 501b26510ae3bbdf9333b83addcd4e5c4214346d (diff) | |
| download | linux-b3f78e74986546a6da5d28c24e627d95d17f79ec.tar.xz | |
mm: vmalloc must set pte via arch code
Patch series "Fixes for pte encapsulation bypasses", v3.
A series to improve the encapsulation of pte entries by disallowing
non-arch code from directly dereferencing pte_t pointers.
This patch (of 4):
It is bad practice to directly set pte entries within a pte table.
Instead all modifications must go through arch-provided helpers such as
set_pte_at() to give the arch code visibility and allow it to check (and
potentially modify) the operation.
Link: https://lkml.kernel.org/r/20230602092949.545577-1-ryan.roberts@arm.com
Link: https://lkml.kernel.org/r/20230602092949.545577-2-ryan.roberts@arm.com
Fixes: 3e9a9e256b1e ("mm: add a vmap_pfn function")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
| -rw-r--r-- | mm/vmalloc.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 7c32435219b1..9d64a4098c36 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2944,10 +2944,16 @@ struct vmap_pfn_data { static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private) { struct vmap_pfn_data *data = private; + unsigned long pfn = data->pfns[data->idx]; + pte_t ptent; - if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx]))) + if (WARN_ON_ONCE(pfn_valid(pfn))) return -EINVAL; - *pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot)); + + ptent = pte_mkspecial(pfn_pte(pfn, data->prot)); + set_pte_at(&init_mm, addr, pte, ptent); + + data->idx++; return 0; } |