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 4EFD545A29F; Tue, 21 Jul 2026 21:57:52 +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=1784671077; cv=none; b=KD7R3j7+jNTTtBP8NuwsMkXIHHqgkPPaFJaCrHyPUcMxMKIDOfHFV2Ro2aD85BxUmqSG8jE8zyNu3XyylY/8aB9gt28+z9jYn+n30bC1O2aRz4xlRkDIahQXQoYNMWyvLrNt3RtpTtbNNWOoUhh+ZrcpVEPjwRXdfo4Uf8pLtBc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784671077; c=relaxed/simple; bh=blJxiBtVv1Q/fNTjA4FxdaSKuDUhckkZAwSifGjL49c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=oktA7GqmMx5tpJxKXflx1eFAeAB/eqRzkSMTG0f38nMRtkFd2As2/6LSgB15PRHtr9EaMXkWVWoxcu5LfvbFroADGH20Mzd0Mh3KsAKMrTaGSU5HF3f1ABRziWaCI6Y9Ud4uvbXRGj7v5IgkXheuiJO/Ww+RxJ6MRzlhHImH5zs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GP4LKJiH; 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="GP4LKJiH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31F031F000E9; Tue, 21 Jul 2026 21:57:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784671071; bh=HCaKnJfQn4+0DzWaENf5BftJOJJK+nZyRGOpMfUKLOM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GP4LKJiHZvuf1feWDs0paaDhTnnGgB3FYJUXjLzXj87GGM0tQQNCkl/D8bMt0XmVE Z8PJnDZJ7P22Cp61mS5lq+ms7mBtRsnFbL8k6s4hcCAVo7QjPgxkRcdmx6j4ra0ObS Qj7ICGjIyDJWuL/GWJYpdceFwOjricKR1QubOc1M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Lianqin Hu , Mathias Nyman Subject: [PATCH 5.15 081/843] usb: xhci: Fix sleep in atomic context in xhci_free_streams() Date: Tue, 21 Jul 2026 17:15:16 +0200 Message-ID: <20260721152407.822019781@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152405.946368001@linuxfoundation.org> References: <20260721152405.946368001@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 5.15-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 @@ -3710,6 +3710,7 @@ 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; @@ -3770,10 +3771,15 @@ 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. @@ -3783,6 +3789,9 @@ 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; }