From 2b626dc134d38d0001b98acf8c7293b6bc5ee86d Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Wed, 3 Feb 2010 17:10:22 +0100 Subject: [PATCH] USB: cdc-acm: fix possible deadlock with multiple openers The lock must be dropped before usb_autopm_interface_put() is called Signed-off-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-acm.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 5155ff2b228..b97f9309c82 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -553,7 +553,7 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) acm = acm_table[tty->index]; if (!acm || !acm->dev) - goto err_out; + goto out; else rv = 0; @@ -569,8 +569,9 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) mutex_lock(&acm->mutex); if (acm->port.count++) { + mutex_unlock(&acm->mutex); usb_autopm_put_interface(acm->control); - goto done; + goto out; } acm->ctrlurb->dev = acm->dev; @@ -599,18 +600,18 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) set_bit(ASYNCB_INITIALIZED, &acm->port.flags); rv = tty_port_block_til_ready(&acm->port, tty, filp); tasklet_schedule(&acm->urb_task); -done: + mutex_unlock(&acm->mutex); -err_out: +out: mutex_unlock(&open_mutex); return rv; full_bailout: usb_kill_urb(acm->ctrlurb); bail_out: - usb_autopm_put_interface(acm->control); acm->port.count--; mutex_unlock(&acm->mutex); + usb_autopm_put_interface(acm->control); early_bail: mutex_unlock(&open_mutex); tty_port_tty_set(&acm->port, NULL); -- 2.39.3