From: Xiyu Yang xiyuyang19@fudan.edu.cn
[ Upstream commit 57a66838e1494cd881b7f4e110ec685736e8e3ca ]
gasket_sysfs_put_attr() invokes get_mapping(), which returns a reference of the specified gasket_sysfs_mapping object to "mapping" with increased refcnt.
When gasket_sysfs_put_attr() returns, local variable "mapping" becomes invalid, so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one path of gasket_sysfs_put_attr(). When mapping attribute is unknown, the function forgets to decrease the refcnt increased by get_mapping(), causing a refcnt leak.
Fix this issue by calling put_mapping() when put attribute fails due to unknown attribute.
Signed-off-by: Xiyu Yang xiyuyang19@fudan.edu.cn Signed-off-by: Xin Tan tanxin.ctf@gmail.com Link: https://lore.kernel.org/r/1587618895-13660-1-git-send-email-xiyuyang19@fudan... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/staging/gasket/gasket_sysfs.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/staging/gasket/gasket_sysfs.c b/drivers/staging/gasket/gasket_sysfs.c index fc45f0d13e87..9c982f1c0881 100644 --- a/drivers/staging/gasket/gasket_sysfs.c +++ b/drivers/staging/gasket/gasket_sysfs.c @@ -343,6 +343,7 @@ void gasket_sysfs_put_attr(struct device *device,
dev_err(device, "Unable to put unknown attribute: %s\n", attr->attr.attr.name); + put_mapping(mapping); } EXPORT_SYMBOL(gasket_sysfs_put_attr);