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authorMark Hairgrove <mhairgrove@nvidia.com>2017-10-13 15:57:30 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-10-13 16:18:32 -0700
commite20d103b6c37038ca27409f746f0b3351bcd0c44 (patch)
treee1970efcd1f2792fc95c2fbd9054c59cb83c578a
parent997301a860fca1a05ab8e383a8039b65f8abeb1e (diff)
downloadlinux-sh-e20d103b6c37038ca27409f746f0b3351bcd0c44.tar.gz
mm/migrate: fix indexing bug (off by one) and avoid out of bound access
Index was incremented before last use and thus the second array could dereference to an invalid address (not mentioning the fact that it did not properly clear the entry we intended to clear). Link: http://lkml.kernel.org/r/1506973525-16491-1-git-send-email-jglisse@redhat.com Fixes: 8315ada7f095bf ("mm/migrate: allow migrate_vma() to alloc new page on empty entry") Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/migrate.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 6954c1435833..e00814ca390e 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2146,8 +2146,9 @@ static int migrate_vma_collect_hole(unsigned long start,
unsigned long addr;
for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) {
- migrate->src[migrate->npages++] = MIGRATE_PFN_MIGRATE;
+ migrate->src[migrate->npages] = MIGRATE_PFN_MIGRATE;
migrate->dst[migrate->npages] = 0;
+ migrate->npages++;
migrate->cpages++;
}