From 114aa35d06d4920c537b72f9fa935de5dd205260 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Fri, 30 Mar 2018 13:22:06 -0700 Subject: [PATCH] netfilter: conntrack: silent a memory leak warning The following memory leak is false postive: unreferenced object 0xffff8f37f156fb38 (size 128): comm "softirq", pid 0, jiffies 4294899665 (age 11.292s) hex dump (first 32 bytes): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk 00 00 00 00 30 00 20 00 48 6b 6b 6b 6b 6b 6b 6b ....0. .Hkkkkkkk backtrace: [<000000004fda266a>] __kmalloc_track_caller+0x10d/0x141 [<000000007b0a7e3c>] __krealloc+0x45/0x62 [<00000000d08e0bfb>] nf_ct_ext_add+0xdc/0x133 [<0000000099b47fd8>] init_conntrack+0x1b1/0x392 [<0000000086dc36ec>] nf_conntrack_in+0x1ee/0x34b [<00000000940592de>] nf_hook_slow+0x36/0x95 [<00000000d1bd4da7>] nf_hook.constprop.43+0x1c3/0x1dd [<00000000c3673266>] __ip_local_out+0xae/0xb4 [<000000003e4192a6>] ip_local_out+0x17/0x33 [<00000000b64356de>] igmp_ifc_timer_expire+0x23e/0x26f [<000000006a8f3032>] call_timer_fn+0x14c/0x2a5 [<00000000650c1725>] __run_timers.part.34+0x150/0x182 [<0000000090e6946e>] run_timer_softirq+0x2a/0x4c [<000000004d1e7293>] __do_softirq+0x1d1/0x3c2 [<000000004643557d>] irq_exit+0x53/0xa2 [<0000000029ddee8f>] smp_apic_timer_interrupt+0x22a/0x235 because __krealloc() is not supposed to release the old memory and it is released later via kfree_rcu(). Since this is the only external user of __krealloc(), just mark it as not leak here. Signed-off-by: Cong Wang Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_extend.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/netfilter/nf_conntrack_extend.c b/net/netfilter/nf_conntrack_extend.c index 9fe0ddc333fb..bd71a828ebde 100644 --- a/net/netfilter/nf_conntrack_extend.c +++ b/net/netfilter/nf_conntrack_extend.c @@ -71,6 +71,7 @@ void *nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp) rcu_read_unlock(); alloc = max(newlen, NF_CT_EXT_PREALLOC); + kmemleak_not_leak(old); new = __krealloc(old, alloc, gfp); if (!new) return NULL;