From mboxrd@z Thu Jan 1 00:00:00 1970 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 31B86332EA2; Fri, 7 Aug 2026 14:46:05 +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=1786113967; cv=none; b=aiHiPJS+u6uaRu4+/wTEOjLuVV8xSX47Gh5fL5ZVBpypOyseag+pQLzrCPf6SEsjawYKpwWukaBosMBNVO1a/E0b9kkXBdl4Bq/4vKn8F2L9rCkGJj8RCC8B9PkQvAmAnDL3RkSJYMroDyC0Vxz5W9Jtt7sHXByZY0YCqfvDFWE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786113967; c=relaxed/simple; bh=FzinT3ZrAnicJGAoqgpkpH/2CubMRSd80ZOvbDpeVz4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UxVM4zvP6YYl/kIWwUGfHFcdGPxhKKriXLgoxb94y2LMkcNTkk9aZh9k9PNnGcG2IeM9IUEQBOd6i/hSak4tjwUNeiMT5umcLk6lQUgO/qIzzfD7pw3fJ3NdfrDbLyDxHBXsnCVo9J8wJXKqJs03+Cz5FKwlm2XL8fKVXdNswQ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ntnHP4nf; 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="ntnHP4nf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 393361F000E9; Fri, 7 Aug 2026 14:46:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786113965; bh=BByeBei8p8NlMudHrPm7oU5JCBpiYQoixs5CfPK6JD8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ntnHP4nfXNY9Gppa1QAAPiBhVZQI4+CDO6hbRHhTuScdlfrdmotdItGs+/qAk7m9q n+qBf3dDnx3AOHO/ovsBW1tmHblmdHp205RtuU1yxfecM31yCTPDY7YAMfpCtOTcAx 6+BdY62Q2AcfmzHf+rohsA6t/N//7z82zQukjEO8= 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 6.12 097/337] Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp Date: Fri, 7 Aug 2026 16:35:00 +0200 Message-ID: <20260807143420.642739490@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143418.516897842@linuxfoundation.org> References: <20260807143418.516897842@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 6.12-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 56337f164d306..c876f986b27f5 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -4796,6 +4796,10 @@ 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); @@ -4841,6 +4845,7 @@ static int l2cap_le_connect_rsp(struct l2cap_conn *conn, } l2cap_chan_unlock(chan); + l2cap_chan_put(chan); return err; } -- 2.53.0