[PATCH 5.13 164/266] Bluetooth: L2CAP: Fix invalid access on ECRED Connection response

Greg Kroah-Hartman
2021-07-15T19:39:17Z

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

[ Upstream commit de895b43932cb47e69480540be7eca289af24f23 ]

The use of l2cap_chan_del is not safe under a loop using
list_for_each_entry.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/bluetooth/l2cap_core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 9b6e57204f51..9908aa53a682 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -6066,7 +6066,7 @@ static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn,
struct l2cap_ecred_conn_rsp *rsp = (void *) data;
struct hci_conn *hcon = conn->hcon;
u16 mtu, mps, credits, result;
- struct l2cap_chan *chan;
+ struct l2cap_chan *chan, *tmp;
int err = 0, sec_level;
int i = 0;

@@ -6085,7 +6085,7 @@ static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn,

cmd_len -= sizeof(*rsp);

- list_for_each_entry(chan, &conn->chan_l, list) {
+ list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
u16 dcid;

if (chan->ident != cmd->ident ||
--
2.30.2