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 AC1FA2139C9; Sat, 10 Jan 2026 22:38:53 +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=1768084733; cv=none; b=QS4sxIEWnrmZZlLvtGdBtBWBzs7eGpKSAkJTTJ7ojRbNpgJaSjpfqjcmyRv5LDL0WjQ9NsEyj//+ZZsXCbgOZ6K6/xFlQx6YpPRltl/RU4SgKHkBTXfjrEaamCTLKSeaBiMTzXnFJOZdFjHLzrJzCag5JBCN5PQT6C0+ZdaiuZw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768084733; c=relaxed/simple; bh=cFy/T8mSd2Wo1IgsveCGgRX5Nc2k/3aNLJOImE3w8ps=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hM7FavA2lsfRegZZyvN8QJHI5IzlT/cHE6g69R33PaFBc1XCj94rNpbnf3eFVCzgsWeA5fnsUpv+sbDIX1wdh4agXqoQV5XEMnhdnBSa5I75t7KG7gKdM57y0cXR4w9s6RpJzMSWO+brJ/mKO5nMKwIJKR7pR51jD3KHCTb8pj4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JWGyJctg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JWGyJctg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A49B5C4CEF1; Sat, 10 Jan 2026 22:38:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768084733; bh=cFy/T8mSd2Wo1IgsveCGgRX5Nc2k/3aNLJOImE3w8ps=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JWGyJctgiaOTE5J/oaNd6UyEsH3ebSC9qVWBv42kFEYPYZzJ4pSPGcwPHdsOR6mPa 8WT/huszHE3h0a7OlG2vs2+sqGgptCoH2roltntnoX2sPcWYAw6NoT163nMPDlOKKj 6vA8NVU7DBaarPVuQh557RfcRAXU7GNej1I5rqnW5ASqgCOdFxWiMrn0X9ovDhJfUS Lln/bIjpTCx13vdJwvDTfAxXC38kjr/V8ad0mpLoQluUrwq95VL1lmXQhyUFwtR8Xn xtoU+O+PzCJWb2GxLFRwTdAqP7MYxQDgCNsZWNQyQ/d3n4nt33nNV48vIA/n45zyD2 zXgLJZnMMd3uw== From: Jakub Kicinski To: mkl@pengutronix.de Cc: Jakub Kicinski , netdev@vger.kernel.org, mailhol@kernel.org, ondrej.ille@gmail.com, linux-can@vger.kernel.org, davem@davemloft.net, kernel@pengutronix.de, swilczek.lx@gmail.com, pisa@fel.cvut.cz, syzbot+e8cb6691a7cf68256cb8@syzkaller.appspotmail.com, stable@vger.kernel.org Subject: Re: [net,2/3] can: gs_usb: gs_usb_receive_bulk_callback(): fix URB memory leak Date: Sat, 10 Jan 2026 14:38:36 -0800 Message-ID: <20260110223836.3890248-1-kuba@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260109135311.576033-3-mkl@pengutronix.de> References: <20260109135311.576033-3-mkl@pengutronix.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This is an AI-generated review of your patch. For local reproduction steps see https://netdev-ai.bots.linux.dev/ai-local.html --- can: gs_usb: gs_usb_receive_bulk_callback(): fix URB memory leak This patch fixes a memory leak by re-anchoring the URB in gs_usb_receive_bulk_callback() before resubmission. The USB framework unanchors URBs before calling the completion callback, so the URB needs to be re-anchored to be tracked by usb_kill_anchored_urbs() in gs_can_close(). Link: https://patch.msgid.link/20260105-gs_usb-fix-memory-leak-v2-1-cc6ed6438034@pengutronix.de > diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c > index a0233e550a5a..d093babbc320 100644 > --- a/drivers/net/can/usb/gs_usb.c > +++ b/drivers/net/can/usb/gs_usb.c > @@ -751,6 +751,8 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) > hf, parent->hf_size_rx, > gs_usb_receive_bulk_callback, parent); > > + usb_anchor_urb(urb, &parent->rx_submitted); > + > rc = usb_submit_urb(urb, GFP_ATOMIC); If usb_submit_urb() fails here, the URB remains anchored but is never submitted. When gs_can_close() later calls usb_kill_anchored_urbs(), it iterates over anchored URBs and calls usb_kill_urb() on each one. For URBs that were never successfully submitted, use_count is 0, so usb_kill_urb() returns without unanchoring them. This causes usb_kill_anchored_urbs() to loop infinitely on the same URB since the anchor list never becomes empty. Other CAN USB drivers handle this by calling usb_unanchor_urb() when submission fails. For example, peak_usb_read_bulk_callback() does: usb_anchor_urb(urb, &dev->rx_submitted); err = usb_submit_urb(urb, GFP_ATOMIC); if (!err) return; usb_unanchor_urb(urb); Should similar error handling be added here to avoid potential hangs when closing the device after a URB submission failure? > > /* USB failure take down all interfaces */ > if (rc == -ENODEV) { [ ... ]