[patch 10/37] NET: Fix packet classidier NULL pointer OOPS

Greg KH
2007-03-30T21:20:26Z

[-- Attachment #1: net-fix-packet-classidier-null-pointer-oops.patch --]
[-- Type: text/plain, Size: 1376 bytes --]

-stable review patch. If anyone has any objections, please let us know.

------------------
From: Patrick McHardy <kaber@trash.net>

[NET_SCHED]: cls_basic: fix NULL pointer dereference

cls_basic doesn't allocate tp->root before it is linked into the
active classifier list, resulting in a NULL pointer dereference
when packets hit the classifier before its ->change function is
called.

Reported by Chris Madden <chris@reflexsecurity.com>

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
net/sched/cls_basic.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)

--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -82,6 +82,13 @@ static void basic_put(struct tcf_proto *

static int basic_init(struct tcf_proto *tp)
{
+ struct basic_head *head;
+
+ head = kzalloc(sizeof(*head), GFP_KERNEL);
+ if (head == NULL)
+ return -ENOBUFS;
+ INIT_LIST_HEAD(&head->flist);
+ tp->root = head;
return 0;
}

@@ -177,15 +184,6 @@ static int basic_change(struct tcf_proto
}

err = -ENOBUFS;
- if (head == NULL) {
- head = kzalloc(sizeof(*head), GFP_KERNEL);
- if (head == NULL)
- goto errout;
-
- INIT_LIST_HEAD(&head->flist);
- tp->root = head;
- }
-
f = kzalloc(sizeof(*f), GFP_KERNEL);
if (f == NULL)
goto errout;

--