diff options
| -rw-r--r-- | drivers/tty/n_gsm.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 3778687f748b..0988aaaf2670 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2889,6 +2889,10 @@ static int gsmtty_install(struct tty_driver *driver, struct tty_struct *tty) gsm = gsm_mux[mux]; if (gsm->dead) return -EL2HLT; + /* If DLCI 0 is not yet fully open return an error. This is ok from a locking + perspective as we don't have to worry about this if DLCI0 is lost */ + if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN) + return -EL2NSYNC; dlci = gsm->dlci[line]; if (dlci == NULL) { alloc = true; |