kmemleak report from network usage

kmemleak report from network usage

[Zdenek Kabelac]

Hi


Recently I'm running kernel with kmemleak.

Here are some frequently repeating messages:

Are they false positives or some real leaks?

 unreferenced object 0xffff880139e5ec78 (size 96):
  comm "NetworkManager", pid 1505, jiffies 4294887099
  backtrace:
    [<ffffffff810ff6f2>] create_object+0x142/0x2d0
    [<ffffffff810ff9a6>] kmemleak_alloc+0x26/0x60
    [<ffffffff810fb083>] kmem_cache_alloc+0x133/0x1a0
    [<ffffffff810a0947>] request_threaded_irq+0xb7/0x250
    [<ffffffffa00d9003>] e1000_request_irq+0x1f3/0x280 [e1000e]
    [<ffffffffa00dc8f0>] e1000_open+0x3f0/0x4c4 [e1000e]
    [<ffffffff812f32f1>] dev_open+0xa1/0x100
    [<ffffffff812f2956>] dev_change_flags+0x96/0x1c0
    [<ffffffff812feb92>] do_setlink+0x212/0x490
    [<ffffffff812ff442>] rtnl_setlink+0x122/0x160
    [<ffffffff812fe70f>] rtnetlink_rcv_msg+0x1df/0x220
    [<ffffffff8130a349>] netlink_rcv_skb+0xa9/0xd0
    [<ffffffff812fe515>] rtnetlink_rcv+0x25/0x40
    [<ffffffff81309bbd>] netlink_unicast+0x29d/0x2f0
    [<ffffffff8130ada2>] netlink_sendmsg+0x222/0x310
    [<ffffffff812e1acb>] sock_sendmsg+0x10b/0x140


unreferenced object 0xffff8800b2a6d180 (size 328):
  comm "softirq", pid 0, jiffies 4295453369
  backtrace:
    [<ffffffff810ff6f2>] create_object+0x142/0x2d0
    [<ffffffff810ff9a6>] kmemleak_alloc+0x26/0x60
    [<ffffffff810fb083>] kmem_cache_alloc+0x133/0x1a0
    [<ffffffff812f8af0>] dst_alloc+0x30/0x80
    [<ffffffff81311643>] ip_route_input+0x1f3/0x1200
    [<ffffffff81314299>] ip_rcv_finish+0x279/0x400
    [<ffffffff81314b0b>] ip_rcv+0x25b/0x330
    [<ffffffff812f3a99>] netif_receive_skb+0x339/0x430
    [<ffffffff812f3d68>] napi_skb_finish+0x58/0x70
    [<ffffffff812f4349>] napi_gro_receive+0x39/0x50
    [<ffffffffa00d77a2>] e1000_receive_skb+0x52/0x60 [e1000e]
    [<ffffffffa00d91b1>] e1000_clean_rx_irq+0x121/0x440 [e1000e]
    [<ffffffffa00d7f2e>] e1000_clean+0x7e/0x280 [e1000e]
    [<ffffffff812f45a0>] net_rx_action+0x170/0x270
    [<ffffffff81052d6c>] __do_softirq+0xbc/0x200
    [<ffffffff8100d2dc>] call_softirq+0x1c/0x50

unreferenced object 0xffff8800b2a6ce00 (size 328):
  comm "cupsd", pid 1460, jiffies 4295453973
  backtrace:
    [<ffffffff810ff6f2>] create_object+0x142/0x2d0
    [<ffffffff810ff9a6>] kmemleak_alloc+0x26/0x60
    [<ffffffff810fb083>] kmem_cache_alloc+0x133/0x1a0
    [<ffffffff812f8af0>] dst_alloc+0x30/0x80
    [<ffffffff81312b8e>] __ip_route_output_key+0x45e/0xb30
    [<ffffffff81313296>] ip_route_output_flow+0x36/0x2c0
    [<ffffffff8133b839>] udp_sendmsg+0x659/0x7c0
    [<ffffffff81342de9>] inet_sendmsg+0x29/0x60
    [<ffffffff812e1acb>] sock_sendmsg+0x10b/0x140
    [<ffffffff812e1e75>] sys_sendto+0xf5/0x130
    [<ffffffff8100c09b>] system_call_fastpath+0x16/0x1b
    [<ffffffffffffffff>] 0xffffffffffffffff




My system - Lenovo T61  x86_64 SMP kernel, C2D, 4GB

Zdenek

Re: kmemleak report from network usage

[Catalin Marinas]

Hi Zdenek,

On Fri, 2009-07-31 at 14:21 +0200, Zdenek Kabelac wrote:
> Recently I'm running kernel with kmemleak.

Which kernel version?

> Here are some frequently repeating messages:
> 
> Are they false positives or some real leaks?

Could be either (but it depends on the kernel version as well since
there were some kmemleak fixes during the -rc stages).

Can you merge the "kmemleak-fixes" branch from
git://linux-arm.org/linux-2.6.git (or just pick
http://www.linux-arm.org/git?p=linux-2.6.git;a=commitdiff;h=4d2b5efa46639b704fd5db1ccd3bdf51cadda50e which ensures that all thread stacks are scanned)?

Are the same leaks still reported reported after a few
"echo scan > /sys/kernel/debug/kmemleak"? If not, they are just
transient leaks, happening especially on SMP systems. If they are still
present, could you please also post the relevant .config entries?

Thanks.

-- 
Catalin