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authorDavid S. Miller <davem@davemloft.net>2017-06-30 12:43:08 -0400
committerDavid S. Miller <davem@davemloft.net>2017-06-30 12:43:08 -0400
commitb07911593719828cac023bdcf6bf4da1c9ba546f (patch)
treec4d2f66e6f2506e5b5439ffca0449e646f677b33 /mm/vmalloc.c
parent52a623bd6189b6ea8f06a0d7594c7604deaab24a (diff)
parent4d8a991d460d4fa4829beaffdcba45a217ca0fa7 (diff)
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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
A set of overlapping changes in macvlan and the rocker driver, nothing serious. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'mm/vmalloc.c')
-rw-r--r--mm/vmalloc.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 34a1c3e46ed7..ecc97f74ab18 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -287,10 +287,21 @@ struct page *vmalloc_to_page(const void *vmalloc_addr)
if (p4d_none(*p4d))
return NULL;
pud = pud_offset(p4d, addr);
- if (pud_none(*pud))
+
+ /*
+ * Don't dereference bad PUD or PMD (below) entries. This will also
+ * identify huge mappings, which we may encounter on architectures
+ * that define CONFIG_HAVE_ARCH_HUGE_VMAP=y. Such regions will be
+ * identified as vmalloc addresses by is_vmalloc_addr(), but are
+ * not [unambiguously] associated with a struct page, so there is
+ * no correct value to return for them.
+ */
+ WARN_ON_ONCE(pud_bad(*pud));
+ if (pud_none(*pud) || pud_bad(*pud))
return NULL;
pmd = pmd_offset(pud, addr);
- if (pmd_none(*pmd))
+ WARN_ON_ONCE(pmd_bad(*pmd));
+ if (pmd_none(*pmd) || pmd_bad(*pmd))
return NULL;
ptep = pte_offset_map(pmd, addr);