diff options
| author | Luiz Augusto von Dentz | 2026-02-17 13:29:43 -0500 |
|---|---|---|
| committer | Sasha Levin | 2026-03-04 07:20:40 -0500 |
| commit | 21842c0dc4d39f316dea21ff1fa6db6d0dc0bbe7 (patch) | |
| tree | 06ff2934bf5df0737fdb6e6ace1725c343fff009 /net | |
| parent | c859b45cc71ace07bdfbd95dd40f69b3c639ec84 (diff) | |
Bluetooth: L2CAP: Fix not checking output MTU is acceptable on L2CAP_ECRED_CONN_REQ
[ Upstream commit a8d1d73c81d1e70d2aa49fdaf59d933bb783ffe5 ]
Upon receiving L2CAP_ECRED_CONN_REQ the given MTU shall be checked
against the suggested MTU of the listening socket as that is required
by the likes of PTS L2CAP/ECFC/BV-27-C test which expects
L2CAP_CR_LE_UNACCEPT_PARAMS if the MTU is lowers than socket omtu.
In order to be able to set chan->omtu the code now allows setting
setsockopt(BT_SNDMTU), but it is only allowed when connection has not
been stablished since there is no procedure to reconfigure the output
MTU.
Link: https://github.com/bluez/bluez/issues/1895
Fixes: 15f02b910562 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/bluetooth/l2cap_core.c | 8 | ||||
| -rw-r--r-- | net/bluetooth/l2cap_sock.c | 15 |
2 files changed, 19 insertions, 4 deletions
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 685e8fb07d70..c0dbad9e8713 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -6116,6 +6116,14 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, goto unlock; } + /* Check if the listening channel has set an output MTU then the + * requested MTU shall be less than or equal to that value. + */ + if (pchan->omtu && mtu < pchan->omtu) { + result = L2CAP_CR_LE_UNACCEPT_PARAMS; + goto unlock; + } + result = L2CAP_CR_LE_SUCCESS; for (i = 0; i < num_scid; i++) { diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 7b822445f8ce..fbad03527905 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1062,10 +1062,17 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, break; } - /* Setting is not supported as it's the remote side that - * decides this. - */ - err = -EPERM; + /* Only allow setting output MTU when not connected */ + if (sk->sk_state == BT_CONNECTED) { + err = -EISCONN; + break; + } + + err = copy_safe_from_sockptr(&mtu, sizeof(mtu), optval, optlen); + if (err) + break; + + chan->omtu = mtu; break; case BT_RCVMTU: |