| Message ID | 1499101594-22421-1-git-send-email-eduval@amazon.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Eduardo Valentin <eduval@amazon.com> 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 <stable@vger.kernel.org> # v4.9+ > Reviewed-by: Vallish Vaidyeshwara <vallish@amazon.com> > Signed-off-by: Eduardo Valentin <eduval@amazon.com> 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 <eduval@amazon.com> > 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 <stable@vger.kernel.org> # v4.9+ > > Reviewed-by: Vallish Vaidyeshwara <vallish@amazon.com> > > Signed-off-by: Eduardo Valentin <eduval@amazon.com> > > 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.
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 <eduval@amazon.com> > > 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 <stable@vger.kernel.org> # v4.9+ > > > Reviewed-by: Vallish Vaidyeshwara <vallish@amazon.com> > > > Signed-off-by: Eduardo Valentin <eduval@amazon.com> > > > > 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
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;
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 <stable@vger.kernel.org> # v4.9+ Reviewed-by: Vallish Vaidyeshwara <vallish@amazon.com> Signed-off-by: Eduardo Valentin <eduval@amazon.com> --- net/bridge/br_mdb.c | 3 +++ 1 file changed, 3 insertions(+)