From: Shuah Khan <sk...@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: sta...@vger.kernel.org Reported-and-tested-by: syzbot+a93fba6d384346a76...@syzkaller.appspotmail.com Signed-off-by: Shuah Khan <sk...@linuxfoundation.org> Link: https://lore.kernel.org/r/c5c8723d3f29dfe3d759cfaafa7dd16b0dfe2918.1616807117.git.sk...@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gre...@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); }
