[patch 16/73] X25: Add missing x25_neigh_put

Greg KH
2008-02-07T00:01:53Z

[-- Attachment #1: x25-add-missing-x25_neigh_put.patch --]
[-- Type: text/plain, Size: 1760 bytes --]

2.6.23-stable review patch. If anyone has any objections, please let us know.
------------------
From: Julia Lawall <julia@diku.dk>

[X25]: Add missing x25_neigh_put

[ Upstream commit: 76975f8a3186dae501584d0155ea410464f62815 ]

The function x25_get_neigh increments a reference count. At the point of
the second goto out, the result of calling x25_get_neigh is only stored in
a local variable, and thus no one outside the function will be able to
decrease the reference count. Thus, x25_neigh_put should be called before
the return in this case.

The problem was found using the following semantic match.
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>

@@
type T,T1,T2;
identifier E;
statement S;
expression x1,x2,x3;
int ret;
@@

T E;
...
* if ((E = x25_get_neigh(...)) == NULL)
S
... when != x25_neigh_put(...,(T1)E,...)
when != if (E != NULL) { ... x25_neigh_put(...,(T1)E,...); ...}
when != x1 = (T1)E
when != E = x3;
when any
if (...) {
... when != x25_neigh_put(...,(T2)E,...)
when != if (E != NULL) { ... x25_neigh_put(...,(T2)E,...); ...}
when != x2 = (T2)E
(
* return;
|
* return ret;
)
}
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
net/x25/x25_forward.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/net/x25/x25_forward.c
+++ b/net/x25/x25_forward.c
@@ -118,13 +118,14 @@ int x25_forward_data(int lci, struct x25
goto out;

if ( (skbn = pskb_copy(skb, GFP_ATOMIC)) == NULL){
- goto out;
+ goto output;

}
x25_transmit_link(skbn, nb);

- x25_neigh_put(nb);
rc = 1;
+output:
+ x25_neigh_put(nb);
out:
return rc;
}

--