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Mon, 11 May 2026 09:23:15 -0700 (PDT) Received: from lvondent-mobl5 ([72.188.211.115]) by smtp.gmail.com with ESMTPSA id 71dfb90a1353d-574a6ef15e0sm19218095e0c.17.2026.05.11.09.23.14 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 May 2026 09:23:15 -0700 (PDT) From: Luiz Augusto von Dentz To: linux-bluetooth@vger.kernel.org Subject: [PATCH v1] Bluetooth: L2CAP: Fix possible crash on l2cap_ecred_conn_rsp Date: Mon, 11 May 2026 12:23:06 -0400 Message-ID: <20260511162306.654747-1-luiz.dentz@gmail.com> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-bluetooth@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Luiz Augusto von Dentz If dcid is received for an already-assigned destination CID the spec requires that both channels to be discarded, but calling l2cap_chan_del may invalidate the tmp cursor created by list_for_each_entry_safe and in fact it is the wrong procedure as the chan->dcid may be assigned previously it really needs to be disconnected using l2cap_send_disconn_req otherwise the remote peer would have no idea that it shall consider to be disconnected. Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/l2cap_core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index fdccd62ccca8..71846849e5b0 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -5293,7 +5293,11 @@ static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn, l2cap_chan_unlock(chan); chan = __l2cap_get_chan_by_dcid(conn, dcid); l2cap_chan_lock(chan); - l2cap_chan_del(chan, ECONNRESET); + /* Disconnect the original channel as it may be + * considered connected since dcid has already been + * assigned. + */ + l2cap_send_disconn_req(chan, ECONNRESET); l2cap_chan_unlock(chan); continue; } -- 2.53.0