diff mbox series

[RFC,5/8] CDC-WDM: fix race reporting errors in flush

Message ID 20200921112052.27943-6-oneukum@suse.com (mailing list archive)
State New, archived
Headers show
Series [RFC,1/8] CDC-WDM: fix hangs in flush() | expand

Commit Message

Oliver Neukum Sept. 21, 2020, 11:20 a.m. UTC 
In case a race was lost and multiple fds used,
an error could be reported multiple times. To fix
this a spinlock must be taken.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/class/cdc-wdm.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 40661b9f6775..89929f6438e3 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -614,8 +614,11 @@  static int wdm_flush(struct file *file, fl_owner_t id)
 		return -EIO;
 	if (rv < 0)
 		return -EINTR;
+
+	spin_lock_irq(&desc->iuspin);
 	rv = desc->werr;
 	desc->werr = 0;
+	spin_unlock_irq(&desc->iuspin);
 
 	return usb_translate_errors(rv);
 }