[PATCH AUTOSEL for 3.18 041/102] libceph: NULL deref on crush_decode() error path

From: Sasha Levin
Date: Mon Mar 19 2018 - 12:42:48 EST


From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ Upstream commit 293dffaad8d500e1a5336eeb90d544cf40d4fbd8 ]

If there is not enough space then ceph_decode_32_safe() does a goto bad.
We need to return an error code in that situation. The current code
returns ERR_PTR(0) which is NULL. The callers are not expecting that
and it results in a NULL dereference.

Fixes: f24e9980eb86 ("ceph: OSD client")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
net/ceph/osdmap.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index 8bb2e0c1cb50..c2f815d44914 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -270,6 +270,7 @@ static struct crush_map *crush_decode(void *pbyval, void *end)
u32 yes;
struct crush_rule *r;

+ err = -EINVAL;
ceph_decode_32_safe(p, end, yes, bad);
if (!yes) {
dout("crush_decode NO rule %d off %x %p to %p\n",
--
2.14.1