From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5D8112E2F0D; Tue, 8 Jul 2025 17:03:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751994189; cv=none; b=ZU5wSYXkFBMv9Dd1+kO8ijM5bwKNpaOnYJtk+0EgsDqGS/Xtymt644gUSd9Bz783T5CL+dWHlub8lE0jyttKMWZ4BLP086Ks7ZJlJea5l3TvJzJjhc+3jmNQs4GaL6nLrcmOCR4408qhazVO0FOtRIYq4vUARjyxstfOF0ciWTU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751994189; c=relaxed/simple; bh=Vhpp7M5Mh6cRSlMnFW4AIl/tJ5mV5CBfhIpS84hcZx8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YKLM/kBoDs99K+NJ4OHS4+D0wNaGqCQAEVnl1OYRQRCFZJRMRVQd9aImU8gRk+nUGyklLnIN4ZOWLBiAIlfzhpQmq+zyv5s+674d55G49MmhLZi8KcOO8Xrofa4aTU00o8qvrJ7ADePzzfQS7kn/7pmyOC+uPs6kOtbTbuBTkRM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vogndQdx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="vogndQdx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8358BC4CEF5; Tue, 8 Jul 2025 17:03:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1751994188; bh=Vhpp7M5Mh6cRSlMnFW4AIl/tJ5mV5CBfhIpS84hcZx8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vogndQdxM4/bgDdIszNRh+7zKqjw6LpQ3WaO8J970768IoxPKIaIvZGdZ4PyEK1oB AYp6pVg3yllZ/xT3s5JY1/fTcm360Hdn0QfhktOhL3ow+IDLVeHXm9Fn+liTw2lqwL NZwYdpokDtN528P04P1bGV0IOAJ9Zd14PRdHwINM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Andrei Kuchynski , Heikki Krogerus Subject: [PATCH 5.15 155/160] usb: typec: displayport: Fix potential deadlock Date: Tue, 8 Jul 2025 18:23:12 +0200 Message-ID: <20250708162235.598200962@linuxfoundation.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250708162231.503362020@linuxfoundation.org> References: <20250708162231.503362020@linuxfoundation.org> User-Agent: quilt/0.68 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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrei Kuchynski commit 099cf1fbb8afc3771f408109f62bdec66f85160e upstream. The deadlock can occur due to a recursive lock acquisition of `cros_typec_altmode_data::mutex`. The call chain is as follows: 1. cros_typec_altmode_work() acquires the mutex 2. typec_altmode_vdm() -> dp_altmode_vdm() -> 3. typec_altmode_exit() -> cros_typec_altmode_exit() 4. cros_typec_altmode_exit() attempts to acquire the mutex again To prevent this, defer the `typec_altmode_exit()` call by scheduling it rather than calling it directly from within the mutex-protected context. Cc: stable Fixes: b4b38ffb38c9 ("usb: typec: displayport: Receive DP Status Update NAK request exit dp altmode") Signed-off-by: Andrei Kuchynski Reviewed-by: Heikki Krogerus Link: https://lore.kernel.org/r/20250624133246.3936737-1-akuchynski@chromium.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/typec/altmodes/displayport.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/usb/typec/altmodes/displayport.c +++ b/drivers/usb/typec/altmodes/displayport.c @@ -299,8 +299,7 @@ static int dp_altmode_vdm(struct typec_a case CMDT_RSP_NAK: switch (cmd) { case DP_CMD_STATUS_UPDATE: - if (typec_altmode_exit(alt)) - dev_err(&dp->alt->dev, "Exit Mode Failed!\n"); + dp->state = DP_STATE_EXIT; break; case DP_CMD_CONFIGURE: dp->data.conf = 0;