From: Nicholas Piggin <npiggin@gmail.com>
To: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, Zefan Li <lizefan@huawei.com>,
Jonathan Cameron <Jonathan.Cameron@Huawei.com>,
Christoph Hellwig <hch@infradead.org>,
Christophe Leroy <christophe.leroy@csgroup.eu>
Subject: [PATCH v8 02/12] mm: apply_to_pte_range warn and fail if a large pte is encountered
Date: Sun, 29 Nov 2020 01:25:49 +1000 [thread overview]
Message-ID: <20201128152559.999540-3-npiggin@gmail.com> (raw)
In-Reply-To: <20201128152559.999540-1-npiggin@gmail.com>
apply_to_pte_range might mistake a large pte for bad, or treat it as a
page table, resulting in a crash or corruption. Add a test to warn and
return error if large entries are found.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
mm/memory.c | 66 +++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 49 insertions(+), 17 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index c48f8df6e502..3d0f0bc5d573 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2429,13 +2429,21 @@ static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud,
}
do {
next = pmd_addr_end(addr, end);
- if (create || !pmd_none_or_clear_bad(pmd)) {
- err = apply_to_pte_range(mm, pmd, addr, next, fn, data,
- create, mask);
- if (err)
- break;
+ if (pmd_none(*pmd) && !create)
+ continue;
+ if (WARN_ON_ONCE(pmd_leaf(*pmd)))
+ return -EINVAL;
+ if (!pmd_none(*pmd) && WARN_ON_ONCE(pmd_bad(*pmd))) {
+ if (!create)
+ continue;
+ pmd_clear_bad(pmd);
}
+ err = apply_to_pte_range(mm, pmd, addr, next,
+ fn, data, create, mask);
+ if (err)
+ break;
} while (pmd++, addr = next, addr != end);
+
return err;
}
@@ -2457,13 +2465,21 @@ static int apply_to_pud_range(struct mm_struct *mm, p4d_t *p4d,
}
do {
next = pud_addr_end(addr, end);
- if (create || !pud_none_or_clear_bad(pud)) {
- err = apply_to_pmd_range(mm, pud, addr, next, fn, data,
- create, mask);
- if (err)
- break;
+ if (pud_none(*pud) && !create)
+ continue;
+ if (WARN_ON_ONCE(pud_leaf(*pud)))
+ return -EINVAL;
+ if (!pud_none(*pud) && WARN_ON_ONCE(pud_bad(*pud))) {
+ if (!create)
+ continue;
+ pud_clear_bad(pud);
}
+ err = apply_to_pmd_range(mm, pud, addr, next,
+ fn, data, create, mask);
+ if (err)
+ break;
} while (pud++, addr = next, addr != end);
+
return err;
}
@@ -2485,13 +2501,21 @@ static int apply_to_p4d_range(struct mm_struct *mm, pgd_t *pgd,
}
do {
next = p4d_addr_end(addr, end);
- if (create || !p4d_none_or_clear_bad(p4d)) {
- err = apply_to_pud_range(mm, p4d, addr, next, fn, data,
- create, mask);
- if (err)
- break;
+ if (p4d_none(*p4d) && !create)
+ continue;
+ if (WARN_ON_ONCE(p4d_leaf(*p4d)))
+ return -EINVAL;
+ if (!p4d_none(*p4d) && WARN_ON_ONCE(p4d_bad(*p4d))) {
+ if (!create)
+ continue;
+ p4d_clear_bad(p4d);
}
+ err = apply_to_pud_range(mm, p4d, addr, next,
+ fn, data, create, mask);
+ if (err)
+ break;
} while (p4d++, addr = next, addr != end);
+
return err;
}
@@ -2511,9 +2535,17 @@ static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr,
pgd = pgd_offset(mm, addr);
do {
next = pgd_addr_end(addr, end);
- if (!create && pgd_none_or_clear_bad(pgd))
+ if (pgd_none(*pgd) && !create)
continue;
- err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, create, &mask);
+ if (WARN_ON_ONCE(pgd_leaf(*pgd)))
+ return -EINVAL;
+ if (!pgd_none(*pgd) && WARN_ON_ONCE(pgd_bad(*pgd))) {
+ if (!create)
+ continue;
+ pgd_clear_bad(pgd);
+ }
+ err = apply_to_p4d_range(mm, pgd, addr, next,
+ fn, data, create, &mask);
if (err)
break;
} while (pgd++, addr = next, addr != end);
--
2.23.0
next prev parent reply other threads:[~2020-11-28 21:53 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-28 15:25 [PATCH v8 00/12] huge vmalloc mappings Nicholas Piggin
2020-11-28 15:25 ` [PATCH v8 01/12] mm/vmalloc: fix vmalloc_to_page for huge vmap mappings Nicholas Piggin
2020-11-28 15:25 ` Nicholas Piggin [this message]
2020-11-28 15:25 ` [PATCH v8 03/12] mm/vmalloc: rename vmap_*_range vmap_pages_*_range Nicholas Piggin
2020-11-28 15:25 ` [PATCH v8 04/12] mm/ioremap: rename ioremap_*_range to vmap_*_range Nicholas Piggin
2020-11-28 15:25 ` [PATCH v8 05/12] mm: HUGE_VMAP arch support cleanup Nicholas Piggin
2020-12-01 14:21 ` Catalin Marinas
2020-11-28 15:25 ` [PATCH v8 06/12] powerpc: inline huge vmap supported functions Nicholas Piggin
2020-11-28 15:25 ` [PATCH v8 07/12] arm64: " Nicholas Piggin
2020-11-28 15:25 ` [PATCH v8 08/12] x86: " Nicholas Piggin
2020-11-28 15:25 ` [PATCH v8 09/12] mm: Move vmap_range from mm/ioremap.c to mm/vmalloc.c Nicholas Piggin
2020-11-28 15:25 ` [PATCH v8 10/12] mm/vmalloc: add vmap_range_noflush variant Nicholas Piggin
2020-11-28 15:25 ` [PATCH v8 11/12] mm/vmalloc: Hugepage vmalloc mappings Nicholas Piggin
2020-11-28 17:07 ` kernel test robot
2020-11-28 17:41 ` kernel test robot
2020-11-30 20:21 ` Edgecombe, Rick P
2020-11-30 21:42 ` Edgecombe, Rick P
2020-12-04 8:12 ` Nicholas Piggin
2020-12-04 18:33 ` Edgecombe, Rick P
2020-12-05 4:49 ` Nicholas Piggin
2020-11-28 15:25 ` [PATCH v8 12/12] powerpc/64s/radix: Enable huge " Nicholas Piggin
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