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 35AFE2E8DF8; Tue, 15 Jul 2025 13:37:19 +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=1752586640; cv=none; b=a8qklLzuaLArMomtaYbXDOLxdcd8wwvaOi8ENLqweQs8Co1FzOYoDvD/DBltZZwAcAM/7KvEjuoWIl9HSo6qMiijfDF/FDax6qPkuODymx9+P3pKNaBHWQ9cSNcgm9ucLfxTCtT4Nr7V5tPWWKmwWgGIYVk6vgQ6YSTtNex9o0w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752586640; c=relaxed/simple; bh=IMRiQIpYF7wMMgz5aNQSrVE9bdhpaYFvBANroQOlgUo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=N4CncXw4oTyJHk/bfCqn43LaaAvVBx7cohWKCSmi5Nef9w71ypZg0afMac3BIbR69tPMNjO44ku7qR3w5q46iw6M0VQBCdJWJySVdLLaRZODFrtliW3kaC/5RszYGFRyKrbk+MBF4/F4k7WrVgFJRSvSY6e9gHveaCAh+u8jomQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=b0evRp3P; 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="b0evRp3P" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 53744C4CEF1; Tue, 15 Jul 2025 13:37:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1752586639; bh=IMRiQIpYF7wMMgz5aNQSrVE9bdhpaYFvBANroQOlgUo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b0evRp3PzyY55W+gS+5Vz56APDl0q6m8iq7c93TJ3uIM8xuLsYL6Im5+HXTt7IZz2 KQdsibbNJ+1YISb74+EdMiuE79kmqphTHftBIiYtUdK2jCI+ACHdG7lgAHc64eAMLr JvYaPCIi+F0blHwKd6ps6XHsvl7ydUMZfz46U3gs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Andrei Kuchynski , Heikki Krogerus Subject: [PATCH 5.4 100/148] usb: typec: displayport: Fix potential deadlock Date: Tue, 15 Jul 2025 15:13:42 +0200 Message-ID: <20250715130804.318577998@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250715130800.293690950@linuxfoundation.org> References: <20250715130800.293690950@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 5.4-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 @@ -289,8 +289,7 @@ 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;