[PATCH 5.12 140/242] Bluetooth: L2CAP: Fix invalid access if ECRED Reconfigure fails

[Greg Kroah-Hartman]

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

[ Upstream commit 1fa20d7d4aad02206e84b74915819fbe9f81dab3 ]

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

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 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 53ddbee459b9..015f9ecadd0a 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -6244,7 +6244,7 @@ static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn,
 					 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
 					 u8 *data)
 {
-	struct l2cap_chan *chan;
+	struct l2cap_chan *chan, *tmp;
 	struct l2cap_ecred_conn_rsp *rsp = (void *) data;
 	u16 result;
 
@@ -6258,7 +6258,7 @@ static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn,
 	if (!result)
 		return 0;
 
-	list_for_each_entry(chan, &conn->chan_l, list) {
+	list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
 		if (chan->ident != cmd->ident)
 			continue;
 
-- 
2.30.2