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authorJohannes Weiner <hannes@saeurebad.de>2008-04-28 17:15:47 +0000
committerGreg Kroah-Hartman <gregkh@suse.de>2008-05-01 14:44:38 -0700
commitde15f7b048a6fe9df998a4fd854a0ac9eb87b80f (patch)
tree0add65fb2e4e05964fd2eece130e658b2258c07f /mm
parent35a398abdc1b5111b62bca9174bc5ccf973ab6dc (diff)
mm: fix possible off-by-one in walk_pte_range()
commit 556637cdabcd5918c7d4a1a2679b8f86fc81e891 upstream After the loop in walk_pte_range() pte might point to the first address after the pmd it walks. The pte_unmap() is then applied to something bad. Spotted by Roel Kluin and Andreas Schwab. Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Cc: Roel Kluin <12o3l@tiscali.nl> Cc: Andreas Schwab <schwab@suse.de> Acked-by: Matt Mackall <mpm@selenic.com> Acked-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'mm')
-rw-r--r--mm/pagewalk.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 1cf1417ef8b7..0afd2387e507 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -9,11 +9,15 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
int err = 0;
pte = pte_offset_map(pmd, addr);
- do {
+ for (;;) {
err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, private);
if (err)
break;
- } while (pte++, addr += PAGE_SIZE, addr != end);
+ addr += PAGE_SIZE;
+ if (addr == end)
+ break;
+ pte++;
+ }
pte_unmap(pte);
return err;