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Subject[PATCH] staging: gasket: Fix mapping refcnt leak when put attribute fails
Date
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>
---
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
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