[PATCH 2/2] drivers/staging/batman-adv: introduce missing kfree

From: Julia Lawall
Date: Sun Dec 13 2009 - 08:12:21 EST


From: Julia Lawall <julia@xxxxxxx>

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@xxxxxxx>
---
drivers/staging/batman-adv/send.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/staging/batman-adv/send.c b/drivers/staging/batman-adv/send.c
index d724798..eb61750 100644
--- a/drivers/staging/batman-adv/send.c
+++ b/drivers/staging/batman-adv/send.c
@@ -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);
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