Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 45E2B42DA3F; Fri, 7 Aug 2026 15:02:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786114955; cv=none; b=RFP9FLZsQaZzoaaysvGwO9RNMlbMmi0ALO8Dm/dIHYu3HPXvs6RYMxxVwXyvDVLrPkbU5PiTXtnUNbKdK1C1khcY9af3Vz9LhfYtTWsK0T/lZHLnDqdF/AkEkiT7wFShmsUaGMkO3vx6qebgL7QHisCTcYm2HgQGhsy8hYBEM00= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786114955; c=relaxed/simple; bh=MGSR/SNVjshH1NPLHCu8Nbp13iA8xNUKb1G/jSESgOs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YPTSbvOexZSEFikQCNfFpFRozv7nkzHKg9A/kz9ZDqVf+BH70+FZWqfgqZObJVLAfm2peqCf6zzMGhQPfLYK58HHQ49CtuKZ/+/KUqBTlHkFsYk5V+HCx0S6KDpjn65CQzfpK7RH3OrnxT+dpmNy6VaukVVanRIUAkOoarluvns= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Ab4+ycNn; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Ab4+ycNn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A4D81F00A3A; Fri, 7 Aug 2026 15:02:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786114954; bh=sTyv/NWAuo+BolqzCbk8HPw99Q5XL+LhTM98EzUyFkk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Ab4+ycNnnm0JH582iagoGUr7GJ7mvQglBhRc68cw0+dBUzstHea4FTLBH4tEydqfX ik6xkV0/6qggyP0IroHF99v9E5YJqHLmRVnbR00kgCjEX86OA8GwmjL+rZjDbBKCQz p+BIFeX7adtZSS+1gf+LW65MlrM9I+TTYQClx72g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiale Yao , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 6.18 107/396] Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp Date: Fri, 7 Aug 2026 16:34:27 +0200 Message-ID: <20260807143426.602868351@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143424.272339768@linuxfoundation.org> References: <20260807143424.272339768@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiale Yao [ Upstream commit c4740e7f23ff9a8210198d8b4703259e21b9f69d ] l2cap_le_connect_rsp() obtains a channel via __l2cap_get_chan_by_ident() but neither holds a reference nor uses l2cap_chan_hold_unless_zero() before locking and operating on it. A concurrent l2cap_chan_del() triggered by a remote disconnect can free the channel between the lookup and l2cap_chan_lock(), causing a use-after-free. The BR/EDR counterpart l2cap_connect_rsp() and the sibling handler l2cap_le_command_rej() already use l2cap_chan_hold_unless_zero() to safely hold a reference, but l2cap_le_connect_rsp() was left unprotected. Fix by adding l2cap_chan_hold_unless_zero() after the ident lookup and l2cap_chan_put() on the exit path, consistent with other L2CAP response handlers. Fixes: f1496dee9cbd ("Bluetooth: Add initial code for LE L2CAP Connect Request") Assisted-by: Claude:deepseek-v4-pro Signed-off-by: Jiale Yao Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/l2cap_core.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index e04948fb6832e..6133c65b20172 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -4831,6 +4831,10 @@ static int l2cap_le_connect_rsp(struct l2cap_conn *conn, if (!chan) return -EBADSLT; + chan = l2cap_chan_hold_unless_zero(chan); + if (!chan) + return -EBADSLT; + err = 0; l2cap_chan_lock(chan); @@ -4876,6 +4880,7 @@ static int l2cap_le_connect_rsp(struct l2cap_conn *conn, } l2cap_chan_unlock(chan); + l2cap_chan_put(chan); return err; } -- 2.53.0