We currently get the following kmemleak report:
unreferenced object 0xffff8800039d9820 (size 32):
comm "softirq", pid 0, jiffies 4295212383 (age 792.416s)
hex dump (first 32 bytes):
00 0c e0 03 00 88 ff ff ff 02 00 00 00 00 00 00 ................
00 00 00 01 ff 11 00 02 86 dd 00 00 ff ff ff ff ................
backtrace:
[<ffffffff8152b4aa>] kmemleak_alloc+0x4a/0xa0
[<ffffffff811d8ec8>] kmem_cache_alloc_trace+0xb8/0x1c0
[<ffffffffa0389683>] __br_mdb_notify+0x2a3/0x300 [bridge]
[<ffffffffa038a0ce>] br_mdb_notify+0x6e/0x70 [bridge]
[<ffffffffa0386479>] br_multicast_add_group+0x109/0x150 [bridge]
[<ffffffffa0386518>] br_ip6_multicast_add_group+0x58/0x60 [bridge]
[<ffffffffa0387fb5>] br_multicast_rcv+0x1d5/0xdb0 [bridge]
[<ffffffffa037d7cf>] br_handle_frame_finish+0xcf/0x510 [bridge]
[<ffffffffa03a236b>] br_nf_hook_thresh.part.27+0xb/0x10 [br_netfilter]
[<ffffffffa03a3738>] br_nf_hook_thresh+0x48/0xb0 [br_netfilter]
[<ffffffffa03a3fb9>] br_nf_pre_routing_finish_ipv6+0x109/0x1d0 [br_netfilter]
[<ffffffffa03a4400>] br_nf_pre_routing_ipv6+0xd0/0x14c [br_netfilter]
[<ffffffffa03a3c27>] br_nf_pre_routing+0x197/0x3d0 [br_netfilter]
[<ffffffff814a2952>] nf_iterate+0x52/0x60
[<ffffffff814a29bc>] nf_hook_slow+0x5c/0xb0
[<ffffffffa037ddf4>] br_handle_frame+0x1a4/0x2c0 [bridge]
This patch flags the complete_info ptr object as not a leak as it will
get freed when .complete_priv() is called, for the br mdb case, it
will be freed at br_mdb_complete().
Cc: stable <[email protected]> # v4.9+
Reviewed-by: Vallish Vaidyeshwara <[email protected]>
Signed-off-by: Eduardo Valentin <[email protected]>
---
net/bridge/br_mdb.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index b084548..1c81546 100644
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -5,6 +5,7 @@
#include <linux/rculist.h>
#include <linux/skbuff.h>
#include <linux/if_ether.h>
+#include <linux/kmemleak.h>
#include <net/ip.h>
#include <net/netlink.h>
#include <net/switchdev.h>
@@ -319,6 +320,8 @@ static void __br_mdb_notify(struct net_device *dev, struct net_bridge_port *p,
if (port_dev && type == RTM_NEWMDB) {
complete_info = kmalloc(sizeof(*complete_info), GFP_ATOMIC);
if (complete_info) {
+ /* This pointer is freed in br_mdb_complete() */
+ kmemleak_not_leak(complete_info);
complete_info->port = p;
__mdb_entry_to_br_ip(entry, &complete_info->ip);
mdb.obj.complete_priv = complete_info;
--
2.7.4
From: Eduardo Valentin <[email protected]>
Date: Mon, 3 Jul 2017 10:06:34 -0700
> We currently get the following kmemleak report:
...
> This patch flags the complete_info ptr object as not a leak as it will
> get freed when .complete_priv() is called,
We don't call .complete_priv(). We call .complete().
for the br mdb case, it
> will be freed at br_mdb_complete().
>
> Cc: stable <[email protected]> # v4.9+
> Reviewed-by: Vallish Vaidyeshwara <[email protected]>
> Signed-off-by: Eduardo Valentin <[email protected]>
I don't understand why kmemleak cannot see this.
We store the pointer globally when we do the switchdev_port_obv_add()
call and it should be able to see that.
On Tue, Jul 04, 2017 at 01:48:42AM -0700, David Miller wrote:
> From: Eduardo Valentin <[email protected]>
> Date: Mon, 3 Jul 2017 10:06:34 -0700
>
> > We currently get the following kmemleak report:
> ...
> > This patch flags the complete_info ptr object as not a leak as it will
> > get freed when .complete_priv() is called,
>
> We don't call .complete_priv(). We call .complete().
True, I can fix this wording in the commit next version.
>
> for the br mdb case, it
> > will be freed at br_mdb_complete().
> >
> > Cc: stable <[email protected]> # v4.9+
> > Reviewed-by: Vallish Vaidyeshwara <[email protected]>
> > Signed-off-by: Eduardo Valentin <[email protected]>
>
> I don't understand why kmemleak cannot see this.
>
> We store the pointer globally when we do the switchdev_port_obv_add()
> call and it should be able to see that.
I see and agree. But even then I get these reports consistently on RTM_NEWMDB type.
This is why I am proposing marking as a non-kmemleak.
To me, this is only a leak if .complete() never gets called.
--
All the best,
Eduardo Valentin
On Wed, Jul 05, 2017 at 09:05:14AM -0700, Eduardo Valentin wrote:
> On Tue, Jul 04, 2017 at 01:48:42AM -0700, David Miller wrote:
> > From: Eduardo Valentin <[email protected]>
> > Date: Mon, 3 Jul 2017 10:06:34 -0700
> >
> > > We currently get the following kmemleak report:
> > ...
> > > This patch flags the complete_info ptr object as not a leak as it will
> > > get freed when .complete_priv() is called,
> >
> > We don't call .complete_priv(). We call .complete().
>
> True, I can fix this wording in the commit next version.
>
> >
> > for the br mdb case, it
> > > will be freed at br_mdb_complete().
> > >
> > > Cc: stable <[email protected]> # v4.9+
> > > Reviewed-by: Vallish Vaidyeshwara <[email protected]>
> > > Signed-off-by: Eduardo Valentin <[email protected]>
> >
> > I don't understand why kmemleak cannot see this.
> >
> > We store the pointer globally when we do the switchdev_port_obv_add()
> > call and it should be able to see that.
>
> I see and agree. But even then I get these reports consistently on RTM_NEWMDB type.
> This is why I am proposing marking as a non-kmemleak.
>
> To me, this is only a leak if .complete() never gets called.
Ok. So, in fact, I believe the problem I am seeing in more when switchdev_port_obj_add() fails.
I will send a patch for that.
>
>
> --
> All the best,
> Eduardo Valentin
--
All the best,
Eduardo Valentin