From fe814b5b0f3042f1a583734497e726ee53783cc1 Mon Sep 17 00:00:00 2001 From: Avichal Rakesh Date: Thu, 4 Jan 2024 13:50:08 -0800 Subject: usb: gadget: uvc: Fix use are free during STREAMOFF There is a path that may lead to freed memory being referenced, causing kernel panics. The kernel panic has the following stack trace: Workqueue: uvcgadget uvcg_video_pump.c51fb85fece46625450f86adbf92c56c.cfi_jt pstate: 60c00085 (nZCv daIf +PAN +UAO -TCO BTYPE=--) pc : __list_del_entry_valid+0xc0/0xd4 lr : __list_del_entry_valid+0xc0/0xd4 Call trace: __list_del_entry_valid+0xc0/0xd4 uvc_video_free_request+0x60/0x98 uvcg_video_pump+0x1cc/0x204 process_one_work+0x21c/0x4b8 worker_thread+0x29c/0x574 kthread+0x158/0x1b0 ret_from_fork+0x10/0x30 The root cause is that uvcg_video_usb_req_queue frees the uvc_request if is_enabled is false and returns an error status. video_pump also frees the associated request if uvcg_video_usb_req_queue returns an error status, leading to double free and accessing garbage memory. To fix the issue, this patch removes freeing logic from uvcg_video_usb_req_queue, and lets the callers to the function handle queueing errors as they see fit. Fixes: 6acba0345b68 ("usb:gadget:uvc Do not use worker thread to pump isoc usb requests") Tested-by: Avichal Rakesh Signed-off-by: Avichal Rakesh Link: https://lore.kernel.org/r/20240104215009.2252452-1-arakesh@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/uvc_video.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'drivers/usb/gadget') diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index 98ba524c27f5..7f18dc471be3 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -276,10 +276,9 @@ static int uvcg_video_usb_req_queue(struct uvc_video *video, bool is_bulk = video->max_payload_size; struct list_head *list = NULL; - if (!video->is_enabled) { - uvc_video_free_request(req->context, video->ep); + if (!video->is_enabled) return -ENODEV; - } + if (queue_to_ep) { struct uvc_request *ureq = req->context; /* @@ -464,8 +463,15 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) * and this thread for isoc endpoints. */ ret = uvcg_video_usb_req_queue(video, to_queue, !is_bulk); - if (ret < 0) + if (ret < 0) { + /* + * Endpoint error, but the stream is still enabled. + * Put request back in req_free for it to be cleaned + * up later. + */ uvcg_queue_cancel(queue, 0); + list_add_tail(&to_queue->list, &video->req_free); + } } else { uvc_video_free_request(ureq, ep); } -- cgit v1.2.3