[PATCH] staging: gasket: Fix mapping refcnt leak when put attribute fails
From: Xiyu Yang
Date: Thu Apr 23 2020 - 01:16:15 EST
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@xxxxxxxxxxxx>
Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx>
---
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 a2d67c28f530..f24edc38c27b 100644
--- a/drivers/staging/gasket/gasket_sysfs.c
+++ b/drivers/staging/gasket/gasket_sysfs.c
@@ -340,6 +340,7 @@ 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);
--
2.7.4