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 20C2D3CF670; Wed, 30 Sep 2026 18:48:32 +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=1790794113; cv=none; b=oFK0aUsczEqaAnIYS1AWvGlNQdDKJzJcjbxpswjF47TjvUXkpdPAwJLX/Sr4hslm+zyG+p5D6kk1qj2GIDSdiEOEcsU5RQ8vCFDuL9EDNoM8qZME0+k0dob/u/16bmKFxz4I1N1ymX3z/E0Ymb1Zhh0TQrDTmDXXYBAQoJ2yTts= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790794113; c=relaxed/simple; bh=OuJsz9jSrtLGX/VpHGFa6MW5+YNV6wNzq/6yfkLNms8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DbssMOdNVWaAVrt8G17fwvCXT5A3z1B0GUUtgLIoWyXrBaQKqx43nfEUT8GAxhfEhR7rU5pHg5MYbQ9b4GfiEnd/wyNtuQ4NkT3v6p9tpQNHJuJQ3OwFFxx+bY35P04UBBQGEUydx9uPFPDgfxJptFOxYFeZCLW5HR6pKPnweTc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=s/dPZyYR; 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="s/dPZyYR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 754551F000FF; Wed, 30 Sep 2026 18:48:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790794112; bh=qoYiMfUVl23+TvsGVi+k1NaNTVxf3Tax635v2CUd7Q4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=s/dPZyYROZ++sjDIBvh7WdBNvFIj64Whi+QEDeGtZKRZK6QQ19ky7PpCsaGGxV2Yt G/cC/s5vaQO+OSkg1qNyP7u4QuWLBND7uwDjlOeysca2Je2hjW9szCHp6iutL2TKIG XCdVEs3uaUbfHb++nNRK4DZyEYxTOMZvfPR/6Xt8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stepan Ionichev , Sasha Levin Subject: [PATCH 6.6 0094/1193] usb: gadget: goku_udc: avoid NULL deref of dev->driver in INT_USBRESET log Date: Wed, 30 Sep 2026 17:12:58 +0200 Message-ID: <20260930152436.328655561@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152434.301151190@linuxfoundation.org> References: <20260930152434.301151190@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: Stepan Ionichev [ Upstream commit 5bf5e3fba9bc7dfd69701521dbe9809f8ccbdb02 ] goku_irq() handles a number of bus events under a single ep0 path. It already guards the gadget driver suspend/resume callbacks against a NULL ->driver: if (dev->gadget.speed != USB_SPEED_UNKNOWN && dev->driver && dev->driver->resume) { spin_unlock(&dev->lock); dev->driver->resume(&dev->gadget); ... } but the very next branch unconditionally dereferences dev->driver when an INT_USBRESET arrives: if (stat & INT_USBRESET) { ACK(INT_USBRESET); INFO(dev, "USB reset done, gadget %s\n", dev->driver->driver.name); } If the controller raises INT_USBRESET before any gadget driver has been bound (or after one has been unbound), dev->driver is NULL and the printk dereferences NULL. smatch flags the inconsistency: drivers/usb/gadget/udc/goku_udc.c:1618 goku_irq() error: we previously assumed 'dev->driver' could be null (see line 1607) Fall back to a placeholder when the gadget driver is not bound. No functional change while a gadget driver is bound. Signed-off-by: Stepan Ionichev Link: https://patch.msgid.link/20260509110636.19762-1-sozdayvek@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/gadget/udc/goku_udc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/udc/goku_udc.c b/drivers/usb/gadget/udc/goku_udc.c index 5ffb3d5c635be..f9b094b04847e 100644 --- a/drivers/usb/gadget/udc/goku_udc.c +++ b/drivers/usb/gadget/udc/goku_udc.c @@ -1616,7 +1616,8 @@ static irqreturn_t goku_irq(int irq, void *_dev) if (stat & INT_USBRESET) { /* hub reset done */ ACK(INT_USBRESET); INFO(dev, "USB reset done, gadget %s\n", - dev->driver->driver.name); + dev->driver ? dev->driver->driver.name : + ""); } // and INT_ERR on some endpoint's crc/bitstuff/... problem } -- 2.53.0