From: Xin Long lucien.xin@gmail.com
[ Upstream commit 9464d0b68f11a9bc768370c3260ec02b3550447b ]
Currently in nf_conntrack_hash_check_insert(), when it fails in nf_ct_ext_valid_pre/post(), NF_CT_STAT_INC() will be called in the preemptible context, a call trace can be triggered:
BUG: using __this_cpu_add() in preemptible [00000000] code: conntrack/1636 caller is nf_conntrack_hash_check_insert+0x45/0x430 [nf_conntrack] Call Trace: <TASK> dump_stack_lvl+0x33/0x46 check_preemption_disabled+0xc3/0xf0 nf_conntrack_hash_check_insert+0x45/0x430 [nf_conntrack] ctnetlink_create_conntrack+0x3cd/0x4e0 [nf_conntrack_netlink] ctnetlink_new_conntrack+0x1c0/0x450 [nf_conntrack_netlink] nfnetlink_rcv_msg+0x277/0x2f0 [nfnetlink] netlink_rcv_skb+0x50/0x100 nfnetlink_rcv+0x65/0x144 [nfnetlink] netlink_unicast+0x1ae/0x290 netlink_sendmsg+0x257/0x4f0 sock_sendmsg+0x5f/0x70
This patch is to fix it by changing to use NF_CT_STAT_INC_ATOMIC() for nf_ct_ext_valid_pre/post() check in nf_conntrack_hash_check_insert(), as well as nf_ct_ext_valid_post() in __nf_conntrack_confirm().
Note that nf_ct_ext_valid_pre() check in __nf_conntrack_confirm() is safe to use NF_CT_STAT_INC(), as it's under local_bh_disable().
Fixes: c56716c69ce1 ("netfilter: extensions: introduce extension genid count") Signed-off-by: Xin Long lucien.xin@gmail.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nf_conntrack_core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 60289c074eef..df46e9a35e47 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -891,7 +891,7 @@ nf_conntrack_hash_check_insert(struct nf_conn *ct) zone = nf_ct_zone(ct);
if (!nf_ct_ext_valid_pre(ct->ext)) { - NF_CT_STAT_INC(net, insert_failed); + NF_CT_STAT_INC_ATOMIC(net, insert_failed); return -ETIMEDOUT; }
@@ -938,7 +938,7 @@ nf_conntrack_hash_check_insert(struct nf_conn *ct)
if (!nf_ct_ext_valid_post(ct->ext)) { nf_ct_kill(ct); - NF_CT_STAT_INC(net, drop); + NF_CT_STAT_INC_ATOMIC(net, drop); return -ETIMEDOUT; }
@@ -1275,7 +1275,7 @@ __nf_conntrack_confirm(struct sk_buff *skb) */ if (!nf_ct_ext_valid_post(ct->ext)) { nf_ct_kill(ct); - NF_CT_STAT_INC(net, drop); + NF_CT_STAT_INC_ATOMIC(net, drop); return NF_DROP; }