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 67A9932ED39; Wed, 3 Dec 2025 16:59:12 +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=1764781152; cv=none; b=qucbyQFm+TZiby0W4h4i5n3lo53pR1Aub1YV/ASTLsTqp/gnzc2TZJ5vT5PzOs7RI0WE9sP4jdh9JP2DhfIycZWv8kO+N+Cj2mK737ohWUWRl0TBapnOG6muSPUJ2o9mNGi5Pyo+uDloHBydy3UTAOeqFgZs24N0VECsW94pE04= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764781152; c=relaxed/simple; bh=sQNLXABx1b1T2TdhxnceaDFcfsCoBApJRvghha7b6lc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pYrmeBj/U2UQLyMK3hmh+COqw9ri9J9zXKhAuLJDVZKB7CJYuArj/dN/Y/9D5WvqMvUAPkbMb6v4R0oHyYUND+dPrjvQrvkBdihVti4ClneiahHHlyCoCwRv/v4V1yKPRIm/o+Irs0q8Txty+tP8zkJO/NDQdiP2TK8fVcB/tGo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ugEh3HLF; 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="ugEh3HLF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A6CFC4CEF5; Wed, 3 Dec 2025 16:59:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764781151; bh=sQNLXABx1b1T2TdhxnceaDFcfsCoBApJRvghha7b6lc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ugEh3HLF7OPEoT/Rmyy+p34J5g1bbn7CBKmoTIdk7Qmy8Mmndq89aUzhyNjwIZ+J4 0dTasfOwZIqvPH1YBHT6rn/RYNZ9PzZ5j9oV5ZfWgKB/C4QPT2VhLHCQDZ7ogc3dCy JnskJ/zb7P0ZX0/SrzSbXSTtPr3tluSGFuk5XPZ0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Thinh Nguyen , Manish Nagar Subject: [PATCH 6.6 66/93] usb: dwc3: Fix race condition between concurrent dwc3_remove_requests() call paths Date: Wed, 3 Dec 2025 16:29:59 +0100 Message-ID: <20251203152338.965856437@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203152336.494201426@linuxfoundation.org> References: <20251203152336.494201426@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-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Manish Nagar commit e4037689a366743c4233966f0e74bc455820d316 upstream. This patch addresses a race condition caused by unsynchronized execution of multiple call paths invoking `dwc3_remove_requests()`, leading to premature freeing of USB requests and subsequent crashes. Three distinct execution paths interact with `dwc3_remove_requests()`: Path 1: Triggered via `dwc3_gadget_reset_interrupt()` during USB reset handling. The call stack includes: - `dwc3_ep0_reset_state()` - `dwc3_ep0_stall_and_restart()` - `dwc3_ep0_out_start()` - `dwc3_remove_requests()` - `dwc3_gadget_del_and_unmap_request()` Path 2: Also initiated from `dwc3_gadget_reset_interrupt()`, but through `dwc3_stop_active_transfers()`. The call stack includes: - `dwc3_stop_active_transfers()` - `dwc3_remove_requests()` - `dwc3_gadget_del_and_unmap_request()` Path 3: Occurs independently during `adb root` execution, which triggers USB function unbind and bind operations. The sequence includes: - `gserial_disconnect()` - `usb_ep_disable()` - `dwc3_gadget_ep_disable()` - `dwc3_remove_requests()` with `-ESHUTDOWN` status Path 3 operates asynchronously and lacks synchronization with Paths 1 and 2. When Path 3 completes, it disables endpoints and frees 'out' requests. If Paths 1 or 2 are still processing these requests, accessing freed memory leads to a crash due to use-after-free conditions. To fix this added check for request completion and skip processing if already completed and added the request status for ep0 while queue. Fixes: 72246da40f37 ("usb: Introduce DesignWare USB3 DRD Driver") Cc: stable Suggested-by: Thinh Nguyen Acked-by: Thinh Nguyen Signed-off-by: Manish Nagar Link: https://patch.msgid.link/20251120074435.1983091-1-manish.nagar@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc3/ep0.c | 1 + drivers/usb/dwc3/gadget.c | 7 +++++++ 2 files changed, 8 insertions(+) --- a/drivers/usb/dwc3/ep0.c +++ b/drivers/usb/dwc3/ep0.c @@ -94,6 +94,7 @@ static int __dwc3_gadget_ep0_queue(struc req->request.actual = 0; req->request.status = -EINPROGRESS; req->epnum = dep->number; + req->status = DWC3_REQUEST_STATUS_QUEUED; list_add_tail(&req->list, &dep->pending_list); --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -229,6 +229,13 @@ void dwc3_gadget_giveback(struct dwc3_ep { struct dwc3 *dwc = dep->dwc; + /* + * The request might have been processed and completed while the + * spinlock was released. Skip processing if already completed. + */ + if (req->status == DWC3_REQUEST_STATUS_COMPLETED) + return; + dwc3_gadget_del_and_unmap_request(dep, req, status); req->status = DWC3_REQUEST_STATUS_COMPLETED;