From: Pavel Skripkin paskripkin@gmail.com
[ Upstream commit 58af3d3d54e87bfc1f936e16c04ade3369d34011 ]
Syzbot reported memory leak in tty_init_dev(). The problem was in unputted tty in ldisc_open()
static int ldisc_open(struct tty_struct *tty) { ... ser->tty = tty_kref_get(tty); ... result = register_netdevice(dev); if (result) { rtnl_unlock(); free_netdev(dev); return -ENODEV; } ... }
Ser pointer is netdev private_data, so after free_netdev() this pointer goes away with unputted tty reference. So, fix it by adding tty_kref_put() before freeing netdev.
Reported-and-tested-by: syzbot+f303e045423e617d2cad@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin paskripkin@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/caif/caif_serial.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c index 32834dad0b83..1243c2e5a86a 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -362,6 +362,7 @@ static int ldisc_open(struct tty_struct *tty) rtnl_lock(); result = register_netdevice(dev); if (result) { + tty_kref_put(tty); rtnl_unlock(); free_netdev(dev); return -ENODEV;