Staging: batman-adv: introduce missing kfree
Julia Lawall [Sun, 13 Dec 2009 13:11:39 +0000 (14:11 +0100)]
Error handling code following a kzalloc should free the allocated data.
Similarly for usb-alloc urb.

The semantic match that finds the first problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,f1,l;
position p1,p2;
expression *ptr != NULL;
@@

x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...x...+> }
(
x->f1 = E
|
 (x->f1 == NULL || ...)
|
 f(...,x->f1,...)
)
...>
(
 return \(0\|<+...x...+>\|ptr\);
|
 return@p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/batman-adv/send.c

index d724798..eb61750 100644 (file)
@@ -363,8 +363,10 @@ void add_bcast_packet_to_list(unsigned char *packet_buff, int packet_len)
                return;
 
        forw_packet->packet_buff = kmalloc(packet_len, GFP_ATOMIC);
-       if (!forw_packet->packet_buff)
+       if (!forw_packet->packet_buff) {
+               kfree(forw_packet);
                return;
+       }
 
        forw_packet->packet_len = packet_len;
        memcpy(forw_packet->packet_buff, packet_buff, forw_packet->packet_len);