| From 363eaa3a450abb4e63bd6e3ad79d1f7a0f717814 Mon Sep 17 00:00:00 2001 |
| From: Shuah Khan <skhan@linuxfoundation.org> |
| Date: Mon, 29 Mar 2021 19:36:51 -0600 |
| Subject: usbip: synchronize event handler with sysfs code paths |
| |
| From: Shuah Khan <skhan@linuxfoundation.org> |
| |
| commit 363eaa3a450abb4e63bd6e3ad79d1f7a0f717814 upstream. |
| |
| Fuzzing uncovered race condition between sysfs code paths in usbip |
| drivers. Device connect/disconnect code paths initiated through |
| sysfs interface are prone to races if disconnect happens during |
| connect and vice versa. |
| |
| Use sysfs_lock to synchronize event handler with sysfs paths |
| in usbip drivers. |
| |
| Cc: stable@vger.kernel.org |
| Reported-and-tested-by: syzbot+a93fba6d384346a761e3@syzkaller.appspotmail.com |
| Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> |
| Link: https://lore.kernel.org/r/c5c8723d3f29dfe3d759cfaafa7dd16b0dfe2918.1616807117.git.skhan@linuxfoundation.org |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/usb/usbip/usbip_event.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/drivers/usb/usbip/usbip_event.c |
| +++ b/drivers/usb/usbip/usbip_event.c |
| @@ -70,6 +70,7 @@ static void event_handler(struct work_st |
| while ((ud = get_event()) != NULL) { |
| usbip_dbg_eh("pending event %lx\n", ud->event); |
| |
| + mutex_lock(&ud->sysfs_lock); |
| /* |
| * NOTE: shutdown must come first. |
| * Shutdown the device. |
| @@ -90,6 +91,7 @@ static void event_handler(struct work_st |
| ud->eh_ops.unusable(ud); |
| unset_event(ud, USBIP_EH_UNUSABLE); |
| } |
| + mutex_unlock(&ud->sysfs_lock); |
| |
| wake_up(&ud->eh_waitq); |
| } |
