[PATCH 3.18 18/47] gadgetfs: fix uninitialized variable in error handling

Greg Kroah-Hartman
2017-04-28T08:36:05Z

From: Arnd Bergmann <arnd@arndb.de>

gcc warns about a bug in 3.18.y:

drivers/usb/gadget/legacy/inode.c:648:10: warning: 'value' may be used

This is caused by the backport of f01d35a15fa0416 from 4.0 to 3.18:
c81fc59be42c6e0 gadgetfs: use-after-free in ->aio_read()

The backported patch was buggy, but the mainline code was rewritten
in a larger patch directly following this one in a way that fixed the
bug.

For stable, we should need only a one-line change to make sure we
return an proper error code. It is very unlikely that anybody ever
ran into the out-of-memory case here in practice, but the compiler
is right in theory.

Fixes: c81fc59be42c ("gadgetfs: use-after-free in ->aio_read()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/gadget/legacy/inode.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -654,6 +654,7 @@ fail:
GFP_KERNEL);
if (!priv->iv) {
kfree(priv);
+ value = -ENOMEM;
goto fail;
}
}