aboutsummaryrefslogtreecommitdiff
path: root/net/ceph/osdmap.c
diff options
context:
space:
mode:
authorXi Wang <xi.wang@gmail.com>2012-02-16 11:55:48 -0500
committerAlex Elder <elder@dreamhost.com>2012-03-22 10:47:45 -0500
commit64486697771cbe219fffcb5c8e2ed9ca4fdf086c (patch)
treea623eebb8105ae8e7585c7faaf171729a9cbadbb /net/ceph/osdmap.c
parent810339ec2fae5cbd0164b8acde7fb65652755864 (diff)
downloadlinux-64486697771cbe219fffcb5c8e2ed9ca4fdf086c.tar.gz
libceph: fix overflow check in crush_decode()
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@gmail.com> Signed-off-by: Sage Weil <sage@newdream.net>
Diffstat (limited to 'net/ceph/osdmap.c')
-rw-r--r--net/ceph/osdmap.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index fd863fe7693..29ad46ec9dc 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) +