On Sat, Jun 04, 2022 at 10:54:54AM +0800, Linyu Yuan wrote:
If a task read/write data in blocking mode, it will wait the completion in ffs_epfile_io(), if function unbind occurs, ffs_func_unbind() will kfree ffs ep, once the task wake up, it still dereference the ffs ep to obtain the request status.
Fix it by moving the request status to io_data which is stack-safe.
Cc: stable@vger.kernel.org # 5.15 Reported-by: Michael Wu michael@allwinnertech.com Tested-by: Michael Wu michael@allwinnertech.com Reviewed-by: John Keeping john@metanate.com Signed-off-by: Linyu Yuan quic_linyyuan@quicinc.com
v2: correct interrupted assignment v3: add Reviewed-by and Reported-by v4: add Tetsed-by from Michael Wu, remove one empty line cc stable kernel
drivers/usb/gadget/function/f_fs.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-)
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 4585ee3..3958c60 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -122,8 +122,6 @@ struct ffs_ep { struct usb_endpoint_descriptor *descs[3]; u8 num;
- int status; /* P: epfile->mutex */
}; struct ffs_epfile { @@ -227,6 +225,9 @@ struct ffs_io_data { bool use_sg; struct ffs_data *ffs;
- int status;
- struct completion done;
}; struct ffs_desc_helper { @@ -707,12 +708,12 @@ static const struct file_operations ffs_ep0_operations = { static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) {
- struct ffs_io_data *io_data = req->context;
- ENTER();
- if (req->context) {
struct ffs_ep *ep = _ep->driver_data;
ep->status = req->status ? req->status : req->actual;
complete(req->context);
- }
- io_data->status = req->status ? req->status : req->actual;
Please do not use ? : lines unless you have to. Please write this as normal if () lines.
thanks,
greg k-h