diff options
| author | Avichal Rakesh <arakesh@google.com> | 2024-01-05 00:50:08 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-05 12:35:57 +0300 |
| commit | fe814b5b0f3042f1a583734497e726ee53783cc1 (patch) | |
| tree | 6b54fa02e753d8d373921ca9eed7c59539dadcef /drivers/usb/gadget | |
| parent | 5962ded777d689cd8bf04454273e32228d7fb71f (diff) | |
| download | linux-fe814b5b0f3042f1a583734497e726ee53783cc1.tar.xz | |
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 <arakesh@google.com>
Signed-off-by: Avichal Rakesh <arakesh@google.com>
Link: https://lore.kernel.org/r/20240104215009.2252452-1-arakesh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/gadget')
| -rw-r--r-- | drivers/usb/gadget/function/uvc_video.c | 14 |
1 files changed, 10 insertions, 4 deletions
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); } |