From: Julia Lawall <julia@diku.dk>
Date: Fri, 11 Sep 2009 06:21:51 +0000 (+0000)
Subject: drivers/net/wan: introduce missing kfree
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=966a5d1b85c45f1b55abbc1b595e0b5ca14b87db;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

drivers/net/wan: introduce missing kfree

Error handling code following a kmalloc should free the allocated data.

The semantic match that finds the 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>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/wan/hdlc_ppp.c b/drivers/net/wan/hdlc_ppp.c
index 72a7cdab4245..b9b9d6b01c0b 100644
--- a/drivers/net/wan/hdlc_ppp.c
+++ b/drivers/net/wan/hdlc_ppp.c
@@ -389,6 +389,7 @@ static void ppp_cp_parse_cr(struct net_device *dev, u16 pid, u8 id,
 	for (opt = data; len; len -= opt[1], opt += opt[1]) {
 		if (len < 2 || len < opt[1]) {
 			dev->stats.rx_errors++;
+			kfree(out);
 			return; /* bad packet, drop silently */
 		}