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 28E3B32470F; Sun, 7 Jun 2026 10:23:05 +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=1780827787; cv=none; b=dFrmWU3xy3MXqRT28TsDLfKqfDWXOofc+K711fKAr/dxcXtoKEk8ZzF3NUtVNCl/tI5IKI71sm+abTPorb6YbF3WA6/1vU/mOeo71gq3MsxPEOSsPIjTm+ryVkCRYMDHXURQNO7zDihQM2lw/1Ik5l3Ta3h5ce6fTnzqMKouRwU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780827787; c=relaxed/simple; bh=ym3YRZqSVlKh/YOe9r9CSovfD43GxTCotNRDa6aWLMs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oBGOlRsoyYUcJalCZ293bmqIN7/OXnzJq5y+WaPjG7w1DqyDZaozqjodkMJY/PnDTuMTFEHWzVjKIrcQfKy4GMQTz1hAM5NdiBD0rUVnFGDO5bB4/ZJ9kRymljcvPTjpMMeGNrPwerg/4Aa7b2XTtFVxC0kSqcLaozt5r5mu2gU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rLMbutw6; 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="rLMbutw6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2FDD01F00893; Sun, 7 Jun 2026 10:23:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780827785; bh=8iFKAsEzFB5NJtLn4Kial7embpMziybK0VCBcJuyUZY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=rLMbutw6B2uO0pSap7laYNq5mZkJOK+73BRydfwCBcTuSz9X4PLQwKF2mWu4aBXi2 oe1GSaACpvT0R+ONg83M7P+J4I3GkN2VsBQ2+STD4hKMX8ua7ai+2xmkKr2DbpW37Y KASHUn28K3YjRLbR0pAsFImPFta92FbydVN63pGY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhenghang Xiao , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 6.12 086/307] Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration success Date: Sun, 7 Jun 2026 11:58:03 +0200 Message-ID: <20260607095730.932447808@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260607095727.647295505@linuxfoundation.org> References: <20260607095727.647295505@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: Zhenghang Xiao [ Upstream commit 00e1950716c6ed67d74777b2db286b0fa23b4be9 ] l2cap_ecred_reconf_rsp() returns early on success without clearing chan->ident. Every other L2CAP response handler (l2cap_ecred_conn_rsp, l2cap_le_connect_rsp, l2cap_config_rsp) clears chan->ident after a successful transaction to prevent the channel from matching subsequent responses with the recycled ident value. A remote attacker that completed a reconfiguration as the peer can replay a failure response with the stale ident, causing the kernel to match and destroy the already-established channel via l2cap_chan_del(chan, ECONNRESET). Clear chan->ident for all matching channels on success, and harden the failure path by using l2cap_chan_hold_unless_zero() consistent with other L2CAP handlers (l2cap_le_command_rej, __l2cap_get_chan_by_ident). Fixes: 15f02b910562 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode") Signed-off-by: Zhenghang Xiao Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/l2cap_core.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index b24e4d8130ddb1..9de5d545966d60 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -5392,14 +5392,20 @@ static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn, BT_DBG("result 0x%4.4x", result); - if (!result) + if (!result) { + list_for_each_entry(chan, &conn->chan_l, list) { + if (chan->ident == cmd->ident) + chan->ident = 0; + } return 0; + } list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) { if (chan->ident != cmd->ident) continue; - l2cap_chan_hold(chan); + if (!l2cap_chan_hold_unless_zero(chan)) + continue; l2cap_chan_lock(chan); l2cap_chan_del(chan, ECONNRESET); -- 2.53.0