linux/include/net
Daniel Borkmann 28e6b67f0b net: sched: fix refcount imbalance in actions
Since commit 55334a5db5 ("net_sched: act: refuse to remove bound action
outside"), we end up with a wrong reference count for a tc action.

Test case 1:

  FOO="1,6 0 0 4294967295,"
  BAR="1,6 0 0 4294967294,"
  tc filter add dev foo parent 1: bpf bytecode "$FOO" flowid 1:1 \
     action bpf bytecode "$FOO"
  tc actions show action bpf
    action order 0: bpf bytecode '1,6 0 0 4294967295' default-action pipe
    index 1 ref 1 bind 1
  tc actions replace action bpf bytecode "$BAR" index 1
  tc actions show action bpf
    action order 0: bpf bytecode '1,6 0 0 4294967294' default-action pipe
    index 1 ref 2 bind 1
  tc actions replace action bpf bytecode "$FOO" index 1
  tc actions show action bpf
    action order 0: bpf bytecode '1,6 0 0 4294967295' default-action pipe
    index 1 ref 3 bind 1

Test case 2:

  FOO="1,6 0 0 4294967295,"
  tc filter add dev foo parent 1: bpf bytecode "$FOO" flowid 1:1 action ok
  tc actions show action gact
    action order 0: gact action pass
    random type none pass val 0
     index 1 ref 1 bind 1
  tc actions add action drop index 1
    RTNETLINK answers: File exists [...]
  tc actions show action gact
    action order 0: gact action pass
     random type none pass val 0
     index 1 ref 2 bind 1
  tc actions add action drop index 1
    RTNETLINK answers: File exists [...]
  tc actions show action gact
    action order 0: gact action pass
     random type none pass val 0
     index 1 ref 3 bind 1

What happens is that in tcf_hash_check(), we check tcf_common for a given
index and increase tcfc_refcnt and conditionally tcfc_bindcnt when we've
found an existing action. Now there are the following cases:

  1) We do a late binding of an action. In that case, we leave the
     tcfc_refcnt/tcfc_bindcnt increased and are done with the ->init()
     handler. This is correctly handeled.

  2) We replace the given action, or we try to add one without replacing
     and find out that the action at a specific index already exists
     (thus, we go out with error in that case).

In case of 2), we have to undo the reference count increase from
tcf_hash_check() in the tcf_hash_check() function. Currently, we fail to
do so because of the 'tcfc_bindcnt > 0' check which bails out early with
an -EPERM error.

Now, while commit 55334a5db5 prevents 'tc actions del action ...' on an
already classifier-bound action to drop the reference count (which could
then become negative, wrap around etc), this restriction only accounts for
invocations outside a specific action's ->init() handler.

One possible solution would be to add a flag thus we possibly trigger
the -EPERM ony in situations where it is indeed relevant.

After the patch, above test cases have correct reference count again.

Fixes: 55334a5db5 ("net_sched: act: refuse to remove bound action outside")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 14:20:39 -07:00
..
9p 9p: switch p9_client_read() to passing struct iov_iter * 2015-04-11 22:28:27 -04:00
bluetooth Bluetooth: hci_core: increase max adv inst 2015-06-18 18:11:53 +02:00
caif caif: fix a signedness bug in cfpkt_iterate() 2015-02-20 17:35:14 -05:00
irda irda: Convert function pointer arrays and uses to const 2014-12-10 15:33:16 -05:00
iucv af_iucv: fix recvmsg by replacing skb_pull() function 2013-04-08 17:16:57 -04:00
netfilter netfilter: fix netns dependencies with conntrack templates 2015-07-20 14:58:19 +02:00
netns netfilter: fix netns dependencies with conntrack templates 2015-07-20 14:58:19 +02:00
nfc NFC: nci: add generic uart support 2015-06-11 23:37:37 +02:00
phonet
sctp sctp: fix ASCONF list handling 2015-06-14 12:55:49 -07:00
tc_act act_bpf: add initial eBPF support for actions 2015-03-20 19:10:44 -04:00
6lowpan.h ieee802154: 6lowpan: rename process_data and lowpan_process_data 2014-10-27 15:51:16 +01:00
act_api.h net: sched: fix refcount imbalance in actions 2015-07-30 14:20:39 -07:00
addrconf.h net: Export IGMP/MLD message validation code 2015-05-04 14:49:23 -04:00
af_ieee802154.h ieee802154: mac802154: remove FSF address 2014-10-25 08:07:30 +02:00
af_rxrpc.h af_rxrpc.h: Remove extern from function prototypes 2013-07-31 17:50:01 -07:00
af_unix.h net/unix: support SCM_SECURITY for stream sockets 2015-06-10 22:49:20 -07:00
af_vsock.h net: Pass kern from net_proto_family.create to sk_alloc 2015-05-11 10:50:17 -04:00
ah.h ipsec: Remove obsolete MAX_AH_AUTH_LEN 2014-09-18 10:54:36 +02:00
arp.h neigh: Factor out ___neigh_lookup_noref 2015-03-04 00:23:23 -05:00
atmclip.h
ax25.h ax25: Stop using sock->sk_protinfo. 2015-06-28 16:55:44 -07:00
ax88796.h
bond_3ad.h bonding: Implement port churn-machine (AD standard 43.4.17). 2015-02-24 16:05:48 -05:00
bond_alb.h net: Move bonding headers under include/net 2014-11-10 13:27:49 -05:00
bond_options.h bonding: Implement user key part of port_key in an AD system. 2015-05-11 10:59:32 -04:00
bonding.h bonding: Implement user key part of port_key in an AD system. 2015-05-11 10:59:32 -04:00
busy_poll.h sched, net: Fixup busy_loop_us_clock() 2014-01-13 17:39:11 +01:00
cfg80211-wext.h
cfg80211.h cfg80211: use RTNL locked reg_can_beacon for IR-relaxation 2015-07-17 15:02:02 +02:00
cfg802154.h nl802154: add support to set cca ed level 2015-05-27 19:29:42 +02:00
checksum.h net: fix sparse error in csum_replace4() 2015-05-17 13:08:29 -04:00
cipso_ipv4.h cipso: don't use IPCB() to locate the CIPSO IP option 2015-02-11 14:46:37 -05:00
cls_cgroup.h cgroup: clean up cgroup_subsys names and initialization 2014-02-08 10:36:58 -05:00
codel.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-05-13 14:31:43 -04:00
compat.h net: switch importing msghdr from userland to {compat_,}import_iovec() 2015-04-09 00:02:26 -04:00
datalink.h net: Move prototype declaration to header file include/net/datalink.h from net/ipx/af_ipx.c 2014-02-09 17:32:50 -08:00
dcbevent.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
dcbnl.h net/dcb: Add IEEE QCN attribute 2015-03-06 21:50:02 -05:00
dn_dev.h dn_dev: add support for IFA_FLAGS nl attribute 2013-12-10 21:50:00 -05:00
dn_fib.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_neigh.h netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
dn_nsp.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_route.h net: Move prototype declaration to appropriate header file from decnet/af_decnet.c 2014-02-09 17:32:49 -08:00
dn.h net: Move prototype declaration to header file include/net/dn.h from net/decnet/af_decnet.c 2014-02-09 17:32:49 -08:00
dsa.h net: dsa: Add basic framework to support ndo_fdb functions 2015-03-29 13:23:54 -07:00
dsfield.h ipv6: Optimize ipv6_change_dsfield(). 2013-01-09 23:59:53 -08:00
dst_ops.h net: Remove protocol from struct dst_ops 2015-03-09 16:06:10 -04:00
dst.h net: make skb_dst_pop routine static 2015-05-12 23:19:49 -04:00
esp.h net: move pskb_put() to core code 2013-11-07 19:28:58 -05:00
ethoc.h net: ethoc: set up MII management bus clock 2014-02-04 20:19:51 -08:00
fib_rules.h net: ipv4 sysctl option to ignore routes when nexthop link is down 2015-06-24 02:15:54 -07:00
firewire.h firewire net, ipv4 arp: Extend hardware address and remove driver-level packet inspection. 2013-03-26 12:32:13 -04:00
flow_dissector.h mpls: Add MPLS entropy label in flow_keys 2015-06-04 15:44:31 -07:00
flow.h ipv4, fib: pass LOOPBACK_IFINDEX instead of 0 to flowi4_iif 2014-04-16 15:05:11 -04:00
flowcache.h flowcache: Make flow cache name space aware 2014-02-12 07:02:11 +01:00
fou.h ip_tunnel: Ops registration for secondary encap (fou, gue) 2014-11-12 15:01:35 -05:00
garp.h garp.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
gen_stats.h net: sched: enable per cpu qstats 2014-09-30 01:02:26 -04:00
genetlink.h net: Introduce possible_net_t 2015-03-12 14:39:40 -04:00
geneve.h geneve: move definition of geneve_hdr() to geneve.h 2015-05-13 15:59:13 -04:00
gre.h gre: Call gso_make_checksum 2014-06-04 22:46:38 -07:00
gro_cells.h ip_tunnel: Create percpu gro_cell 2015-01-18 01:56:32 -05:00
gue.h gue: Protocol constants for remote checksum offload 2014-11-05 16:30:03 -05:00
icmp.h icmp.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
ieee80211_radiotap.h mac80211: propagate STBC / LDPC flags to radiotap 2014-02-06 09:34:58 +01:00
ieee802154_netdev.h mac802154: cleanup llsec param flags 2015-06-12 11:42:29 +02:00
if_inet6.h ipv6: do retries on stable privacy addresses 2015-03-23 22:12:09 -04:00
inet6_connection_sock.h inet: get rid of central tcp/dccp listener timer 2015-03-20 12:40:25 -04:00
inet6_hashtables.h ipv6: get rid of __inet6_hash() 2015-03-18 22:00:35 -04:00
inet_common.h net: Modify sk_alloc to not reference count the netns of kernel sockets. 2015-05-11 10:50:18 -04:00
inet_connection_sock.h tcp: fix child sockets to use system default congestion control if not set 2015-05-31 21:49:14 -07:00
inet_ecn.h tunnel: fix RFC number in comment for INET_ECN_decapsulate() 2014-05-07 15:30:52 -04:00
inet_frag.h inet: frags: remove INET_FRAG_EVICTED and use list_evictor for the test 2015-07-26 21:00:15 -07:00
inet_hashtables.h tcp: fix/cleanup inet_ehash_locks_alloc() 2015-05-26 19:48:46 -04:00
inet_sock.h inet: add IP_BIND_ADDRESS_NO_PORT to overcome bind(0) limitations 2015-06-06 23:57:12 -07:00
inet_timewait_sock.h tcp/dccp: get rid of central timewait timer 2015-04-13 16:40:05 -04:00
inetpeer.h tcp: simplify inetpeer_addr_base use 2015-03-31 13:58:35 -04:00
ip6_checksum.h net: add gro_compute_pseudo functions 2014-08-24 18:09:23 -07:00
ip6_fib.h ipv6: Create percpu rt6_info 2015-05-25 13:25:35 -04:00
ip6_route.h ipv6: Add rt6_get_cookie() function 2015-05-25 13:25:34 -04:00
ip6_tunnel.h udp_tunnel: Pass UDP socket down through udp_tunnel{, 6}_xmit_skb(). 2015-04-07 15:29:08 -04:00
ip_fib.h ipv4: consider TOS in fib_select_default 2015-07-24 22:46:11 -07:00
ip_tunnels.h ipip,gre,vti,sit: implement ndo_get_iflink 2015-04-02 14:05:00 -04:00
ip_vs.h net: Introduce possible_net_t 2015-03-12 14:39:40 -04:00
ip.h ipv6: lock socket in ip6_datagram_connect() 2015-07-15 17:25:51 -07:00
ipcomp.h
ipconfig.h
ipv6.h net: Add full IPv6 addresses to flow_keys 2015-06-04 15:44:30 -07:00
ipx.h switch ipxrtr_route_packet() from iovec to msghdr 2014-11-24 04:28:49 -05:00
iw_handler.h wext: add checked wrappers for adding events/points to streams 2015-02-28 21:31:12 +01:00
lapb.h lapb.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
lib80211.h lib80211: remove unused print_ssid() 2014-10-14 02:18:27 +02:00
llc_c_ac.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_c_ev.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_c_st.h llc: Make llc_conn_ev_qfyr_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_conn.h net: Pass kern from net_proto_family.create to sk_alloc 2015-05-11 10:50:17 -04:00
llc_if.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_pdu.h net: llc: fix order of evaluation in llc_conn_ac_inc_vr_by_1 2014-01-01 22:22:43 -05:00
llc_s_ac.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_s_ev.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_s_st.h llc: Make llc_sap_action_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_sap.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc.h llc: make lock static 2014-01-03 20:56:48 -05:00
mac80211.h mac80211: convert HW flags to unsigned long bitmap 2015-06-10 16:05:36 +02:00
mac802154.h mac802154: fix flags BIT definitions order 2015-06-12 11:43:58 +02:00
mip6.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
mld.h ipv6: mld: answer mldv2 queries with mldv1 reports in mldv1 fallback 2014-09-22 16:23:15 -04:00
mpls.h openvswitch: Add basic MPLS support to kernel 2014-11-05 23:52:33 -08:00
mrp.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-10-01 17:06:14 -04:00
ndisc.h neigh: Factor out ___neigh_lookup_noref 2015-03-04 00:23:23 -05:00
neighbour.h net: neighbour: Add mcast_resolicit to configure the number of multicast resolicitations in PROBE state. 2015-03-20 21:47:40 -04:00
net_namespace.h net: include missing headers in net/net_namespace.h 2015-06-18 21:14:29 +02:00
net_ratelimit.h
netevent.h netevent/netlink.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
netlabel.h netlabel: fix the netlbl_catmap_setlong() dummy function 2014-08-07 20:55:21 -04:00
netlink.h netlink: implement nla_get_in_addr and nla_get_in6_addr 2015-03-31 13:58:35 -04:00
netprio_cgroup.h cgroup: clean up cgroup_subsys names and initialization 2014-02-08 10:36:58 -05:00
netrom.h netrom.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
nexthop.h
nl802154.h nl802154: fix misspelled enum 2015-06-10 12:24:33 +02:00
p8022.h p8022.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
ping.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
pkt_cls.h net: sched: remove tcf_proto from ematch calls 2014-10-06 18:02:32 -04:00
pkt_sched.h net: rename vlan_tx_* helpers since "tx" is misleading there 2015-01-13 17:51:08 -05:00
protocol.h net: Eliminate no_check from protosw 2014-05-23 16:28:53 -04:00
psnap.h psnap.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
raw.h raw/rawv6.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
rawv6.h raw/rawv6.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
red.h reciprocal_divide: update/correction of the algorithm 2014-01-21 23:17:20 -08:00
regulatory.h cfg80211: allow wiphy specific regdomain management 2014-12-17 11:49:55 +01:00
request_sock.h tcp: provide SYN headers for passive connections 2015-05-05 16:02:34 -04:00
rose.h rose.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
route.h ipv4: per cpu uncached list 2015-01-15 18:26:16 -05:00
rtnetlink.h rtnetlink: Mark name argument of rtnl_create_link() const 2015-04-10 12:42:40 -07:00
sch_generic.h net: sched: use counter to break reclassify loops 2015-05-13 15:08:14 -04:00
scm.h scm.h: Remove extern from function prototypes 2013-09-23 01:51:09 -04:00
secure_seq.h inetpeer: get rid of ip_id_count 2014-06-02 11:00:41 -07:00
slhc_vj.h
snmp.h Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
sock.h tcp: fix recv with flags MSG_WAITALL | MSG_PEEK 2015-07-27 01:06:53 -07:00
Space.h drivers: net: Include new header file in sbni.c 2013-12-19 18:51:20 -05:00
stp.h stp.h: Remove extern from function prototypes 2013-09-23 01:51:09 -04:00
switchdev.h switchdev: rename vlan vid_start to vid_begin 2015-06-23 06:56:18 -07:00
tcp_memcontrol.h tcp_memcontrol: Kill struct tcp_memcontrol 2013-10-21 18:43:02 -04:00
tcp_states.h inet: add TCP_NEW_SYN_RECV state 2015-03-12 22:58:12 -04:00
tcp.h tcp: fill shinfo->gso_size at last moment 2015-06-11 16:33:11 -07:00
timewait_sock.h
transp_v6.h ipv6: make IPV6_RECVPKTINFO work for ipv4 datagrams 2014-01-19 19:53:18 -08:00
tso.h net: Add a software TSO helper API 2014-05-22 14:57:15 -04:00
udp_tunnel.h udp_tunnel: Pass UDP socket down through udp_tunnel{, 6}_xmit_skb(). 2015-04-07 15:29:08 -04:00
udp.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
udplite.h net: switch memcpy_fromiovec()/memcpy_fromiovecend() users to copy_from_iter() 2015-02-04 01:34:15 -05:00
vsock_addr.h VSOCK: Move af_vsock.h and vsock_addr.h to include/net 2013-07-27 22:14:06 -07:00
vxlan.h udp_tunnel: Pass UDP socket down through udp_tunnel{, 6}_xmit_skb(). 2015-04-07 15:29:08 -04:00
wext.h wext.h: Remove extern from function prototypes 2013-09-23 16:29:40 -04:00
wimax.h net: treewide: Fix typo found in DocBook/networking.xml 2014-09-05 17:35:28 -07:00
x25.h x25.h: Remove extern from function prototypes 2013-09-23 16:29:41 -04:00
x25device.h
xfrm.h ipsec: Add IV generator information to xfrm_state 2015-05-28 11:23:20 +08:00