From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: Re: [RFC] igmp: address pmc kmemleak from on igmpv3_del_delrec() Date: Mon, 6 Feb 2017 16:32:14 -0800 Message-ID: References: <20170203212047.31653-1-mcgrof@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: David Miller , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Linux Kernel Network Developers , LKML , kernel@kyup.com, liuhangbin@gmail.com To: "Luis R. Rodriguez" Return-path: In-Reply-To: <20170203212047.31653-1-mcgrof@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, Feb 3, 2017 at 1:20 PM, Luis R. Rodriguez wrote: > When we igmpv3_add_delrec() we kzalloc the pmc, but when users > call igmpv3_del_delrec() we never free the pmc. This was caught > by the following kmemleak splat: > > unreferenced object 0xffff99666ff43b40 (size 192): > comm "systemd-resolve", pid 1258, jiffies 4309905600 (age 2138.352s) > hex dump (first 32 bytes): > 00 6a 64 72 66 99 ff ff e0 00 00 fc 00 00 00 00 .jdrf........... > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [] kmemleak_alloc+0x4a/0xa0 > [] kmem_cache_alloc_trace+0x107/0x240 > [] igmp_group_dropped+0xfd/0x270 > [] ip_mc_dec_group+0xaf/0x110 > [] ip_mc_leave_group+0xb6/0x140 > [] do_ip_setsockopt.isra.13+0x4c7/0xed0 > [] ip_setsockopt+0x34/0xb0 > [] udp_setsockopt+0x1b/0x30 > [] sock_common_setsockopt+0x14/0x20 > [] SyS_setsockopt+0x80/0xe0 > [] do_syscall_64+0x5b/0xc0 > [] return_from_SYSCALL_64+0x0/0x6a > [] 0xffffffffffffffff > > Signed-off-by: Luis R. Rodriguez > --- > > I can reproduce this over time on a qemu box running next-20170125. > After running this for a while I no longer see the splat. This needs > confirmation form folks more familiar with the code, hence RFC. If > this is a real fix we need appropriate tags for the patch. Looks good to me. Adding some people who recent touched it to CC. > > net/ipv4/igmp.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c > index 5b15459955f8..44fd86de2823 100644 > --- a/net/ipv4/igmp.c > +++ b/net/ipv4/igmp.c > @@ -1172,6 +1172,7 @@ static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im) > psf->sf_crcount = im->crcount; > } > in_dev_put(pmc->interface); > + kfree(pmc); > } > spin_unlock_bh(&im->lock); > } > -- > 2.11.0 >