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 3F53534107F; Mon, 20 Apr 2026 16:12:45 +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=1776701565; cv=none; b=cSaZPSeLddKaEwCmyRS+uBB/Hj+EEDVzwOk4lKhWMPXSJ1jyW5gUOQlccuh00dBLjOaAP8Oj9iYS1l7jeBNyVW5IwBiuFF/p0qS7JFzgX52P46VD2rT2G21WQozLTXfdZcnrHdtevwyzUKmjFRTFMnQQVUQdh0+TSqrMR/MstDQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776701565; c=relaxed/simple; bh=Ao6p2bksbJxN0X8Otx3vvrBs+x7N09eKMN/YEM6cZQQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=h++deFL2J+Bde9x/tDUiW8uqI5SIVHHlJb6WavyaD/2cM/MTZ8jtlL+tm08n+b6zDyf62xpSPTMSihldiSDIxPD/Cqn5I2/2zjGeVW8IDM3oiONLWLCNdIJ3WW59AJJC9jNSPxjiYhduSiP2He4BR9r9K1nUb7XzDxr8gbCrLQY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tYynj9IH; 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="tYynj9IH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5E1EC19425; Mon, 20 Apr 2026 16:12:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776701565; bh=Ao6p2bksbJxN0X8Otx3vvrBs+x7N09eKMN/YEM6cZQQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tYynj9IHAeDnTUBkUHEMFbeLGo8KAn9vc7+OP5jnlMTjVwfLb5qgdmTGaqNwpOwmV FcKOWoFWKlIds9ROSIRVaEacz5R8pMiZJZO1ejDVwsQQSGnQcB2dL9OAN52x9pdpYH kCXy/2W55GsfTiMTUOtL/pijz8fqswpS0RabKivk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+6ffd76b5405c006a46b7@syzkaller.appspotmail.com, syzbot+f1b20958f93d2d250727@syzkaller.appspotmail.com, Jeongjun Park , Hans Verkuil Subject: [PATCH 6.12 155/162] media: hackrf: fix to not free memory after the device is registered in hackrf_probe() Date: Mon, 20 Apr 2026 17:43:07 +0200 Message-ID: <20260420153932.665429950@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260420153927.006696811@linuxfoundation.org> References: <20260420153927.006696811@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeongjun Park commit 3b7da2b4d0fe014eff181ed37e3bf832eb8ed258 upstream. In hackrf driver, the following race condition occurs: ``` CPU0 CPU1 hackrf_probe() kzalloc(); // alloc hackrf_dev .... v4l2_device_register(); .... fd = sys_open("/path/to/dev"); // open hackrf fd .... v4l2_device_unregister(); .... kfree(); // free hackrf_dev .... sys_ioctl(fd, ...); v4l2_ioctl(); video_is_registered() // UAF!! .... sys_close(fd); v4l2_release() // UAF!! hackrf_video_release() kfree(); // DFB!! ``` When a V4L2 or video device is unregistered, the device node is removed so new open() calls are blocked. However, file descriptors that are already open-and any in-flight I/O-do not terminate immediately; they remain valid until the last reference is dropped and the driver's release() is invoked. Therefore, freeing device memory on the error path after hackrf_probe() has registered dev it will lead to a race to use-after-free vuln, since those already-open handles haven't been released yet. And since release() free memory too, race to use-after-free and double-free vuln occur. To prevent this, if device is registered from probe(), it should be modified to free memory only through release() rather than calling kfree() directly. Cc: Reported-by: syzbot+6ffd76b5405c006a46b7@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=6ffd76b5405c006a46b7 Reported-by: syzbot+f1b20958f93d2d250727@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f1b20958f93d2d250727 Fixes: 8bc4a9ed8504 ("[media] hackrf: add support for transmitter") Signed-off-by: Jeongjun Park Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/hackrf/hackrf.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/media/usb/hackrf/hackrf.c +++ b/drivers/media/usb/hackrf/hackrf.c @@ -1486,7 +1486,7 @@ static int hackrf_probe(struct usb_inter if (ret) { dev_err(dev->dev, "Failed to register as video device (%d)\n", ret); - goto err_v4l2_device_unregister; + goto err_v4l2_device_put; } dev_info(dev->dev, "Registered as %s\n", video_device_node_name(&dev->rx_vdev)); @@ -1515,8 +1515,9 @@ static int hackrf_probe(struct usb_inter return 0; err_video_unregister_device_rx: video_unregister_device(&dev->rx_vdev); -err_v4l2_device_unregister: - v4l2_device_unregister(&dev->v4l2_dev); +err_v4l2_device_put: + v4l2_device_put(&dev->v4l2_dev); + return ret; err_v4l2_ctrl_handler_free_tx: v4l2_ctrl_handler_free(&dev->tx_ctrl_handler); err_v4l2_ctrl_handler_free_rx: