[PATCH AUTOSEL for 4.9 101/281] libceph: NULL deref on crush_decode() error path

[Sasha Levin]

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 d3f6c26425b3..255c0a075e49 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -295,6 +295,7 @@ 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