From 921deb9da15851425ccbb6ee409dc2fd8fbdfe6b Mon Sep 17 00:00:00 2001
From: Udipto Goswami <quic_ugoswami@quicinc.com>
Date: Tue, 24 Jan 2023 14:41:49 +0530
Subject: [PATCH] usb: gadget: f_fs: Fix unbalanced spinlock in __ffs_ep0_queue_wait
Git-commit: 921deb9da15851425ccbb6ee409dc2fd8fbdfe6b
Patch-mainline: v6.2-rc7
References: git-fixes
__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")
Reviewed-by: John Keeping <john@metanate.com>
Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
Link: https://lore.kernel.org/r/20230124091149.18647-1-quic_ugoswami@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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);
--
2.35.3