libceph: fix crush_decode() call site in osdmap_decode()

The size of the memory area feeded to crush_decode() should be limited
not only by osdmap end, but also by the crush map length.  Also, drop
unnecessary dout() (dout() in crush_decode() conveys the same info) and
step past crush map only if it is decoded successfully.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>

1 files changed, 2 insertions, 5 deletions

diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index c39ac624ccc3..d4a6b0df3627 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -802,16 +802,13 @@ static int osdmap_decode(void **p, void *end, struct ceph_osdmap *map)
 
         /* crush */
         ceph_decode_32_safe(p, end, len, e_inval);
-        dout("osdmap_decode crush len %d from off 0x%x\n", len,
-             (int)(*p - start));
-        ceph_decode_need(p, end, len, e_inval);
-        map->crush = crush_decode(*p, end);
-        *p += len;
+        map->crush = crush_decode(*p, min(*p + len, end));
         if (IS_ERR(map->crush)) {
                 err = PTR_ERR(map->crush);
                 map->crush = NULL;
                 goto bad;
         }
+        *p += len;
 
         /* ignore the rest */
         *p = end;