Subject: [PATCH AUTOSEL 5.13 177/189] Bluetooth: L2CAP: Fix invalid access on ECRED Connection response

From: Sasha Levin <[email-masked]>
Date: Tue, 6 Jul 2021 07:13:57 -0400

From: Luiz Augusto von Dentz <[email-masked]>

[ 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 <[email-masked]>
Signed-off-by: Marcel Holtmann <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 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