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 60F3742A15E; Thu, 16 Jul 2026 14:25:08 +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=1784211909; cv=none; b=auPrWbJLsTtsAErOHjvBdFAcNh1UgA/FCItDBeJXzsAzQdIkGMXhljnbIn31bg+zWMQJrteY6xq2LT1DaQ7PB9JhWdL9SkA5vtAffhHAeVfwJ1vES8xxFG686ffwbkMgZCVdPxqSBgL8Jtw5PcL30hYt3iUQjSkxlJL+K06bQP0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784211909; c=relaxed/simple; bh=Ff1l7VJiNflVrEhKDYbtDFYs35M8mrXPGFr46GSWhYc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=VbDJ7pIIOxxHjt0NQ5rRAJDl5GYE1YjauaKiAHLP9WsQPT7s3GBHlrHYuCIBwuRjrhH8zirklnf5KWIWeaWxX+2/sT3cu8TdyK/55UkDuINazM6dabsKFL618XCMklyh4RveanBYi6RZtKzu9R5OMiRDh8fCn5a5kjp7C9M6Mes= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xGghrsED; 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="xGghrsED" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BC2A71F000E9; Thu, 16 Jul 2026 14:25:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784211908; bh=awOw2b8JJfyBlDZ+jQKMVhzV1JmtmTl6pUJ9Jarns9I=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=xGghrsED8fJyRO5So+L91ul/yn1T/2azOpSBCTnzNt3uSGo/WaH1h1/MtCf9+nh+s SRyIt+GJvWJnd6aBXFYTz27CFDZ3Omu7CpF5wnMSj0mp7AFdkMDJsvyrsaLSu9g6pu i2X8H9IXffKGlXsmUPO6ym6mKmm6sypxhIh5lt0E= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Lianqin Hu , Mathias Nyman Subject: [PATCH 6.12 099/349] usb: xhci: Fix sleep in atomic context in xhci_free_streams() Date: Thu, 16 Jul 2026 15:30:33 +0200 Message-ID: <20260716133035.530487461@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133033.287196923@linuxfoundation.org> References: <20260716133033.287196923@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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: 胡连勤 commit 42c37c4b75d38b51d84f31a8e29427f5e06a7c2a upstream. When a USB device with active stream endpoints is disconnected, xhci_free_streams() is called from the hub_event workqueue to free the stream resources. It calls xhci_free_stream_info() while holding xhci->lock with irqs disabled. xhci_free_stream_info() invokes xhci_free_stream_ctx(), which calls dma_free_coherent() for large stream context arrays. dma_free_coherent() can sleep (e.g. via vunmap), triggering a BUG when called from atomic context. Call trace: dma_free_attrs+0x174/0x220 xhci_free_stream_info+0xd0/0x11c xhci_free_streams+0x278/0x37c usb_free_streams+0x98/0xc0 usb_unbind_interface+0x1b8/0x2f8 device_release_driver_internal+0x1d4/0x2cc device_release_driver+0x18/0x28 bus_remove_device+0x160/0x1a4 device_del+0x1ec/0x350 usb_disable_device+0x98/0x214 usb_disconnect+0xf0/0x35c hub_event+0xab4/0x19ec process_one_work+0x278/0x63c Fix this by saving the stream_info pointers and clearing the ep references under the lock, then calling xhci_free_stream_info() outside the lock where sleeping is allowed. Fixes: 8df75f42f8e6 ("USB: xhci: Add memory allocation for USB3 bulk streams.") Cc: stable Signed-off-by: Lianqin Hu Signed-off-by: Mathias Nyman Link: https://patch.msgid.link/20260703144033.483286-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3576,6 +3576,7 @@ static int xhci_free_streams(struct usb_ struct xhci_virt_device *vdev; struct xhci_command *command; struct xhci_input_control_ctx *ctrl_ctx; + struct xhci_stream_info *stream_info[EP_CTX_PER_DEV]; unsigned int ep_index; unsigned long flags; u32 changed_ep_bitmask; @@ -3636,10 +3637,15 @@ static int xhci_free_streams(struct usb_ if (ret < 0) return ret; + /* + * dma_free_coherent() called by xhci_free_stream_info() may sleep, + * so save stream_info pointers and clear references under lock, + * then free the memory outside lock. + */ spin_lock_irqsave(&xhci->lock, flags); for (i = 0; i < num_eps; i++) { ep_index = xhci_get_endpoint_index(&eps[i]->desc); - xhci_free_stream_info(xhci, vdev->eps[ep_index].stream_info); + stream_info[i] = vdev->eps[ep_index].stream_info; vdev->eps[ep_index].stream_info = NULL; /* FIXME Unset maxPstreams in endpoint context and * update deq ptr to point to normal string ring. @@ -3649,6 +3655,9 @@ static int xhci_free_streams(struct usb_ } spin_unlock_irqrestore(&xhci->lock, flags); + for (i = 0; i < num_eps; i++) + xhci_free_stream_info(xhci, stream_info[i]); + return 0; }