Bluetooth: Fix a buffer overflow in mgmt_mesh_add()

[ Upstream commit 2185e0fdbb2137f22a9dd9fcbf6481400d56299b ]

Smatch Warning:
net/bluetooth/mgmt_util.c:375 mgmt_mesh_add() error: __memcpy()
'mesh_tx->param' too small (48 vs 50)

Analysis:

'mesh_tx->param' is array of size 48. This is the destination.
u8 param[sizeof(struct mgmt_cp_mesh_send) + 29]; // 19 + 29 = 48.

But in the caller 'mesh_send' we reject only when len > 50.
len > (MGMT_MESH_SEND_SIZE + 31) // 19 + 31 = 50.

Fixes: b338d91703fa ("Bluetooth: Implement support for Mesh")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Brian Gix <brian.gix@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/bluetooth/mgmt_util.h b/net/bluetooth/mgmt_util.h
index 6a8b7e84293dfd436af59a433f4d82e92497867e..bdf978605d5a85bcbee1c0db1a76065e31a6096e 100644 (file)
--- a/net/bluetooth/mgmt_util.h
+++ b/net/bluetooth/mgmt_util.h
@@ -27,7 +27,7 @@ struct mgmt_mesh_tx {
        struct sock *sk;
        u8 handle;
        u8 instance;
-       u8 param[sizeof(struct mgmt_cp_mesh_send) + 29];
+       u8 param[sizeof(struct mgmt_cp_mesh_send) + 31];
 };
 
 struct mgmt_pending_cmd {