The existing overflow check (n > ULONG_MAX / b) didn't work, because n = ULONG_MAX / b would both bypass the check and still overflow the allocation size a + n * b. The correct check should be (n > (ULONG_MAX - a) / b). Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx> --- net/ceph/osdmap.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index fd863fe..29ad46e 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -283,7 +283,8 @@ static struct crush_map *crush_decode(void *pbyval, void *end) ceph_decode_32_safe(p, end, yes, bad); #if BITS_PER_LONG == 32 err = -EINVAL; - if (yes > ULONG_MAX / sizeof(struct crush_rule_step)) + if (yes > (ULONG_MAX - sizeof(*r)) + / sizeof(struct crush_rule_step)) goto bad; #endif r = c->rules[i] = kmalloc(sizeof(*r) + -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
