diff mbox series

usb: gadget: f_fs: Fix unbalanced spinlock in __ffs_ep0_queue_wait

Message ID 20230124091149.18647-1-quic_ugoswami@quicinc.com (mailing list archive)
State Accepted
Commit 921deb9da15851425ccbb6ee409dc2fd8fbdfe6b
Headers show
Series usb: gadget: f_fs: Fix unbalanced spinlock in __ffs_ep0_queue_wait | expand

Commit Message

Udipto Goswami Jan. 24, 2023, 9:11 a.m. UTC
__ffs_ep0_queue_wait executes holding the spinlock of &ffs->ev.waitq.lock
and unlocks it after the assignments to usb_request are done.
However in the code if the request is already NULL we bail out returning
-EINVAL but never unlocked the spinlock.

Fix this by adding spin_unlock_irq &ffs->ev.waitq.lock before returning.

Fixes: 6a19da111057("usb: gadget: f_fs: Prevent race during ffs_ep0_queue_wait")
Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
---
 drivers/usb/gadget/function/f_fs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

John Keeping Jan. 24, 2023, 10:53 a.m. UTC | #1
On Tue, Jan 24, 2023 at 02:41:49PM +0530, Udipto Goswami wrote:
> __ffs_ep0_queue_wait executes holding the spinlock of &ffs->ev.waitq.lock
> and unlocks it after the assignments to usb_request are done.
> However in the code if the request is already NULL we bail out returning
> -EINVAL but never unlocked the spinlock.
> 
> Fix this by adding spin_unlock_irq &ffs->ev.waitq.lock before returning.
> 
> Fixes: 6a19da111057("usb: gadget: f_fs: Prevent race during ffs_ep0_queue_wait")
> Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>

Reviewed-by: John Keeping <john@metanate.com>

> ---
>  drivers/usb/gadget/function/f_fs.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
> index 523a961b910b..8ad354741380 100644
> --- a/drivers/usb/gadget/function/f_fs.c
> +++ b/drivers/usb/gadget/function/f_fs.c
> @@ -279,8 +279,10 @@ static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
>  	struct usb_request *req = ffs->ep0req;
>  	int ret;
>  
> -	if (!req)
> +	if (!req) {
> +		spin_unlock_irq(&ffs->ev.waitq.lock);
>  		return -EINVAL;
> +	}
>  
>  	req->zero     = len < le16_to_cpu(ffs->ev.setup.wLength);
>  
> -- 
> 2.17.1
>
diff mbox series

Patch

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 523a961b910b..8ad354741380 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -279,8 +279,10 @@  static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
 	struct usb_request *req = ffs->ep0req;
 	int ret;
 
-	if (!req)
+	if (!req) {
+		spin_unlock_irq(&ffs->ev.waitq.lock);
 		return -EINVAL;
+	}
 
 	req->zero     = len < le16_to_cpu(ffs->ev.setup.wLength);