From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Luis R. Rodriguez" Subject: [RFC] igmp: address pmc kmemleak from on igmpv3_del_delrec() Date: Fri, 3 Feb 2017 13:20:47 -0800 Message-ID: <20170203212047.31653-1-mcgrof@kernel.org> Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Luis R. Rodriguez" To: davem@davemloft.net, kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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. 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