linux/net/ipv4
Jiri Wiesner ebaf39e603 ipv4: ipv6: netfilter: Adjust the frag mem limit when truesize changes
The *_frag_reasm() functions are susceptible to miscalculating the byte
count of packet fragments in case the truesize of a head buffer changes.
The truesize member may be changed by the call to skb_unclone(), leaving
the fragment memory limit counter unbalanced even if all fragments are
processed. This miscalculation goes unnoticed as long as the network
namespace which holds the counter is not destroyed.

Should an attempt be made to destroy a network namespace that holds an
unbalanced fragment memory limit counter the cleanup of the namespace
never finishes. The thread handling the cleanup gets stuck in
inet_frags_exit_net() waiting for the percpu counter to reach zero. The
thread is usually in running state with a stacktrace similar to:

 PID: 1073   TASK: ffff880626711440  CPU: 1   COMMAND: "kworker/u48:4"
  #5 [ffff880621563d48] _raw_spin_lock at ffffffff815f5480
  #6 [ffff880621563d48] inet_evict_bucket at ffffffff8158020b
  #7 [ffff880621563d80] inet_frags_exit_net at ffffffff8158051c
  #8 [ffff880621563db0] ops_exit_list at ffffffff814f5856
  #9 [ffff880621563dd8] cleanup_net at ffffffff814f67c0
 #10 [ffff880621563e38] process_one_work at ffffffff81096f14

It is not possible to create new network namespaces, and processes
that call unshare() end up being stuck in uninterruptible sleep state
waiting to acquire the net_mutex.

The bug was observed in the IPv6 netfilter code by Per Sundstrom.
I thank him for his analysis of the problem. The parts of this patch
that apply to IPv4 and IPv6 fragment reassembly are preemptive measures.

Signed-off-by: Jiri Wiesner <jwiesner@suse.com>
Reported-by: Per Sundstrom <per.sundstrom@redqube.se>
Acked-by: Peter Oskolkov <posk@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-05 20:44:46 -08:00
..
bpfilter bpfilter: remove trailing newline 2018-07-24 14:10:42 -07:00
netfilter netfilter: nat: fix double register in masquerade modules 2018-11-27 00:36:46 +01:00
af_inet.c gso_segment: Reset skb->mac_len after modifying network header 2018-09-13 12:09:32 -07:00
ah4.c net-ipv4: remove 2 always zero parameters from ipv4_redirect() 2018-09-26 20:30:55 -07:00
arp.c net: Evict neighbor entries on carrier down 2018-10-12 09:47:39 -07:00
cipso_ipv4.c net/ipv4: defensive cipso option parsing 2018-09-17 19:37:46 -07:00
datagram.c ipv4: Allow sending multicast packets on specific i/f using VRF socket 2018-10-02 22:28:17 -07:00
devinet.c net/{ipv4,ipv6}: Do not put target net if input nsid is invalid 2018-10-25 16:21:31 -07:00
esp4_offload.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2018-07-27 09:33:37 -07:00
esp4.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2018-10-01 22:31:17 -07:00
fib_frontend.c net: Don't return invalid table id error when dumping all families 2018-10-24 14:06:25 -07:00
fib_lookup.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fib_notifier.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fib_rules.c net: fib_rules: add extack support 2018-04-23 10:21:24 -04:00
fib_semantics.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-10-12 21:38:46 -07:00
fib_trie.c net/ipv4: Plumb support for filtering route dumps 2018-10-16 00:13:12 -07:00
fou.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-07-03 10:29:26 +09:00
gre_demux.c ip_gre: fix parsing gre header in ipgre_err 2018-09-16 15:32:59 -07:00
gre_offload.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-07-03 10:29:26 +09:00
icmp.c net-ipv4: remove 2 always zero parameters from ipv4_redirect() 2018-09-26 20:30:55 -07:00
igmp.c ipv4/igmp: fix v1/v2 switchback timeout based on rfc3376, 8.12 2018-10-29 20:26:06 -07:00
inet_connection_sock.c inet: make sure to grab rcu_read_lock before using ireq->ireq_opt 2018-10-02 15:52:12 -07:00
inet_diag.c sock_diag: request _diag module only when the family or proto has been registered 2018-03-12 11:03:42 -04:00
inet_fragment.c inet: frags: better deal with smp races 2018-11-08 18:40:30 -08:00
inet_hashtables.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
inet_timewait_sock.c soreuseport: initialise timewait reuseport field 2018-04-07 22:32:32 -04:00
inetpeer.c inetpeer: fix uninit-value in inet_getpeer 2018-04-09 10:57:35 -04:00
ip_forward.c net: ipv4: Control SKB reprioritization after forwarding 2018-08-01 09:52:30 -07:00
ip_fragment.c ipv4: ipv6: netfilter: Adjust the frag mem limit when truesize changes 2018-12-05 20:44:46 -08:00
ip_gre.c net-ipv4: remove 2 always zero parameters from ipv4_redirect() 2018-09-26 20:30:55 -07:00
ip_input.c net: use skb_list_del_init() to remove from RX sublists 2018-12-05 16:22:05 -08:00
ip_options.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip_output.c net: always initialize pagedlen 2018-11-24 17:42:57 -08:00
ip_sockglue.c net: bpfilter: fix iptables failure if bpfilter_umh is disabled 2018-11-05 17:12:18 -08:00
ip_tunnel_core.c ip_tunnel: don't force DF when MTU is locked 2018-11-17 21:50:55 -08:00
ip_tunnel.c ip_tunnel: be careful when accessing the inner header 2018-09-24 12:27:04 -07:00
ip_vti.c net-ipv4: remove 2 always zero parameters from ipv4_redirect() 2018-09-26 20:30:55 -07:00
ipcomp.c net-ipv4: remove 2 always zero parameters from ipv4_redirect() 2018-09-26 20:30:55 -07:00
ipconfig.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
ipip.c net-ipv4: remove 2 always zero parameters from ipv4_redirect() 2018-09-26 20:30:55 -07:00
ipmr_base.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-10-19 11:03:06 -07:00
ipmr.c net: Don't return invalid table id error when dumping all families 2018-10-24 14:06:25 -07:00
Kconfig net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
Makefile bpf, sockmap: convert to generic sk_msg interface 2018-10-15 12:23:19 -07:00
metrics.c net: common metrics init helper for FIB entries 2018-10-04 21:54:03 -07:00
netfilter.c netfilter: utils: move nf_ip_checksum* from ipv4 to utils 2018-07-16 17:51:48 +02:00
netlink.c ipv4: support sport, dport and ip_proto in RTM_GETROUTE 2018-05-23 15:14:12 -04:00
ping.c ipv4: Allow sending multicast packets on specific i/f using VRF socket 2018-10-02 22:28:17 -07:00
proc.c ip: discard IPv4 datagrams with overlapping segments. 2018-08-05 17:16:46 -07:00
protocol.c
raw_diag.c
raw.c ipv4: Allow sending multicast packets on specific i/f using VRF socket 2018-10-02 22:28:17 -07:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-10-12 21:38:46 -07:00
syncookies.c tcp: provide earliest departure time in skb->tstamp 2018-09-21 19:37:59 -07:00
sysctl_net_ipv4.c net-tcp: /proc/sys/net/ipv4/tcp_probe_interval is a u32 not int 2018-09-26 20:33:21 -07:00
tcp_bbr.c tcp_bbr: centralize code to set gains 2018-10-17 22:22:53 -07:00
tcp_bic.c
tcp_bpf.c bpf: tcp_bpf_recvmsg should return EAGAIN when nonblocking and no data 2018-10-30 23:31:22 +01:00
tcp_cdg.c tcp: cdg: use tcp high resolution clock cache 2018-10-15 22:56:42 -07:00
tcp_cong.c tcp: Namespace-ify sysctl_tcp_default_congestion_control 2017-11-15 14:09:52 +09:00
tcp_cubic.c
tcp_dctcp.c tcp: refactor DCTCP ECN ACK handling 2018-10-10 22:26:00 -07:00
tcp_dctcp.h tcp: refactor DCTCP ECN ACK handling 2018-10-10 22:26:00 -07:00
tcp_diag.c net: sock: replace sk_state_load with inet_sk_state_load and remove sk_state_store 2017-12-20 14:00:25 -05:00
tcp_fastopen.c tcp: pause Fast Open globally after third consecutive timeout 2017-12-13 15:51:12 -05:00
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c net/tcp/illinois: replace broken algorithm reference link 2018-02-28 12:03:47 -05:00
tcp_input.c tcp: address problems caused by EDT misshaps 2018-11-24 17:41:37 -08:00
tcp_ipv4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-10-03 21:00:17 -07:00
tcp_lp.c
tcp_metrics.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
tcp_minisocks.c tcp: do not restart timewait timer on rst reception 2018-08-31 23:10:35 -07:00
tcp_nv.c tcp_nv: fix potential integer overflow in tcpnv_acked 2018-01-31 10:26:30 -05:00
tcp_offload.c tcp: Don't coalesce decrypted and encrypted SKBs 2018-07-16 00:12:09 -07:00
tcp_output.c tcp: fix NULL ref in tail loss probe 2018-12-05 16:34:40 -08:00
tcp_rate.c tcp: introduce tcp_skb_timestamp_us() helper 2018-09-21 19:37:59 -07:00
tcp_recovery.c tcp: introduce tcp_skb_timestamp_us() helper 2018-09-21 19:37:59 -07:00
tcp_scalable.c
tcp_timer.c tcp: fix SNMP TCP timeout under-estimation 2018-11-30 17:22:41 -08:00
tcp_ulp.c tcp, ulp: remove socket lock assertion on ULP cleanup 2018-10-16 12:38:41 -07:00
tcp_vegas.c tcp: fix under-evaluated ssthresh in TCP Vegas 2017-09-29 06:07:00 +01:00
tcp_vegas.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
tunnel4.c inet: whitespace cleanup 2018-02-28 11:43:28 -05:00
udp_diag.c net: diag: document swapped src/dst in udp_dump_one. 2018-10-28 19:27:21 -07:00
udp_impl.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
udp_offload.c udp: gro behind static key 2018-10-05 11:52:38 -07:00
udp_tunnel.c
udp.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
udplite.c proc: introduce proc_create_net{,_data} 2018-05-16 07:24:30 +02:00
xfrm4_input.c xfrm: reset transport header back to network header after all input transforms ahave been applied 2018-09-04 10:26:30 +02:00
xfrm4_mode_beet.c
xfrm4_mode_transport.c xfrm: reset transport header back to network header after all input transforms ahave been applied 2018-09-04 10:26:30 +02:00
xfrm4_mode_tunnel.c xfrm: Verify MAC header exists before overwriting eth_hdr(skb)->h_proto 2018-03-07 10:54:29 +01:00
xfrm4_output.c net: xfrm: use skb_gso_validate_network_len() to check gso sizes 2018-03-04 17:49:17 -05:00
xfrm4_policy.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
xfrm4_protocol.c
xfrm4_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm4_tunnel.c