[PATCH AUTOSEL 5.13 176/189] Bluetooth: L2CAP: Fix invalid access if ECRED Reconfigure fails

Sasha Levin
2021-07-06T11:31:12Z

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

[ 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@oracle.com>
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 b6a88b8256c7..9b6e57204f51 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -6248,7 +6248,7 @@ 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;

@@ -6262,7 +6262,7 @@ 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