This is a note to let you know that I've just added the patch titled atm: fix atm_dev refcnt leaks in atmtcp_remove_persistent to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: atm-fix-atm_dev-refcnt-leaks-in-atmtcp_remove_persis.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit d5190b4a942702f0ab352109cbc285403233a7b1 Author: Xin Xiong <xiongx18@xxxxxxxxxxxx> Date: Wed Jul 29 21:06:59 2020 +0800 atm: fix atm_dev refcnt leaks in atmtcp_remove_persistent [ Upstream commit 51875dad43b44241b46a569493f1e4bfa0386d86 ] atmtcp_remove_persistent() invokes atm_dev_lookup(), which returns a reference of atm_dev with increased refcount or NULL if fails. The refcount leaks issues occur in two error handling paths. If dev_data->persist is zero or PRIV(dev)->vcc isn't NULL, the function returns 0 without decreasing the refcount kept by a local variable, resulting in refcount leaks. Fix the issue by adding atm_dev_put() before returning 0 both when dev_data->persist is zero or PRIV(dev)->vcc isn't NULL. Signed-off-by: Xin Xiong <xiongx18@xxxxxxxxxxxx> Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/atm/atmtcp.c b/drivers/atm/atmtcp.c index 480fa6ffbc090..04fca6db273ef 100644 --- a/drivers/atm/atmtcp.c +++ b/drivers/atm/atmtcp.c @@ -432,9 +432,15 @@ static int atmtcp_remove_persistent(int itf) return -EMEDIUMTYPE; } dev_data = PRIV(dev); - if (!dev_data->persist) return 0; + if (!dev_data->persist) { + atm_dev_put(dev); + return 0; + } dev_data->persist = 0; - if (PRIV(dev)->vcc) return 0; + if (PRIV(dev)->vcc) { + atm_dev_put(dev); + return 0; + } kfree(dev_data); atm_dev_put(dev); atm_dev_deregister(dev);