[PATCH 4.9 100/310] libceph: NULL deref on crush_decode() error path

From: Greg Kroah-Hartman
Date: Wed Apr 11 2018 - 15:58:11 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ceph/osdmap.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -295,6 +295,7 @@ static struct crush_map *crush_decode(vo
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",