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 23E3E424D44; Thu, 16 Jul 2026 13:43:10 +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=1784209393; cv=none; b=mz99k7Zna3fDCM17mOD1R0PJKdTlBFJEAm2M0Md5mD3X9yUFbPUXeqFv4jrlwW8ibUzJ3wBvht787g+8JioUW9iHDc18b3hxYA9Bt8J/p/OFPo0m/kT3DXdqwbx0xuj5/MXGb/6oCGkztXetaNeUOImEPjFtVhpuAH7FAH+38BQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784209393; c=relaxed/simple; bh=DW9FoZo5GXpXkMV3SrY/RQneaWY66d6dHh91XprmNs4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=geEru3DK2lbxzS78A7pHwnXDrbrW7rrn8BAlXRwHnWq/w9c+sqy9rVMCzCDejKofjkj6EA5U6yFa56lW0hLkzALDAQqx3+Le+XucnidFJ5dJdmTlGcABb2SaJtqvNhduoLHfFiocKNLZDud4Yq/g7YWyKH4dV6CM+6Htf/ViaAc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rsSZEIPo; 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="rsSZEIPo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8208E1F00A3D; Thu, 16 Jul 2026 13:43:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784209390; bh=hA1wq9RDzmGVd0ww/AXiczDNuTkuKwGw2Lo/6j+Dj8s=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=rsSZEIPoB2qvyKMbiLA8jmeSssjMZNXWFXPw9StxOm6of65ChnRXznAuSG9j75Kz5 3JfjRPzv8C7L9l4eVr69cTqwmhjxkh3yFDpYOha81siUQ0AVYG5h9U8GTMRBLY/NJB x0sdTSW+9vYXG5/4GGF1kh/3e/MQ3+J+Ocwm1+bg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Lianqin Hu , Mathias Nyman Subject: [PATCH 7.1 124/518] usb: xhci: Fix sleep in atomic context in xhci_free_streams() Date: Thu, 16 Jul 2026 15:26:32 +0200 Message-ID: <20260716133050.570588970@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133047.772246337@linuxfoundation.org> References: <20260716133047.772246337@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 7.1-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 @@ -3788,6 +3788,7 @@ 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; @@ -3848,10 +3849,15 @@ 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. @@ -3861,6 +3867,9 @@ 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; }