KMSAN started reporting an error when accessing ct->timeout for the first time without initialization: BUG: KMSAN: uninit-value in __nf_ct_refresh_acct+0x1ae/0x470 net/netfilter/nf_conntrack_core.c:1765 ... dump_stack+0x173/0x1d0 lib/dump_stack.c:113 kmsan_report+0x131/0x2a0 mm/kmsan/kmsan.c:624 __msan_warning+0x7a/0xf0 mm/kmsan/kmsan_instr.c:310 __nf_ct_refresh_acct+0x1ae/0x470 net/netfilter/nf_conntrack_core.c:1765 nf_ct_refresh_acct ./include/net/netfilter/nf_conntrack.h:201 nf_conntrack_udp_packet+0xb44/0x1040 net/netfilter/nf_conntrack_proto_udp.c:122 nf_conntrack_handle_packet net/netfilter/nf_conntrack_core.c:1605 nf_conntrack_in+0x1250/0x26c9 net/netfilter/nf_conntrack_core.c:1696 ... Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:159 kmsan_kmalloc+0xa9/0x130 mm/kmsan/kmsan_hooks.c:173 kmem_cache_alloc+0x554/0xb10 mm/slub.c:2789 __nf_conntrack_alloc+0x16f/0x690 net/netfilter/nf_conntrack_core.c:1342 init_conntrack+0x6cb/0x2490 net/netfilter/nf_conntrack_core.c:1421 Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> Fixes: cc16921351d8ba1 ("netfilter: conntrack: avoid same-timeout update") Cc: Florian Westphal <fw@xxxxxxxxx> --- net/netfilter/nf_conntrack_core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 82bfbeef46af..a137d4e7f218 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1350,6 +1350,7 @@ __nf_conntrack_alloc(struct net *net, /* save hash for reusing when confirming */ *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash; ct->status = 0; + ct->timeout = 0; write_pnet(&ct->ct_net, net); memset(&ct->__nfct_init_offset[0], 0, offsetof(struct nf_conn, proto) - -- 2.21.0.392.gf8f6787159e-goog