linux/net/sched
Davide Caratti 7c3d825d12 net/sched: act_skbmod: validate the control action inside init()
the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action skbmod set smac 00:c1:a0:c1:a0:00 pass index 90
 # tc actions replace action skbmod \
 > set smac 00:c1:a0:c1:a0:00 goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action skbmod

had the following output:

 src MAC address <00:c1:a0:c1:a0:00>
 src MAC address <00:c1:a0:c1:a0:00>
 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: skbmod goto chain 42 set smac 00:c1:a0:c1:a0:00
          index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 800000002d5c7067 P4D 800000002d5c7067 PUD 77e16067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.0.0-rc4.gotochain_crash+ #536
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffff8987ffd83be0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff8987aeb68800 RCX: ffff8987fa263640
 RDX: 0000000000000000 RSI: ffff8987f51c8802 RDI: 00000000000000a0
 RBP: ffff8987ffd83c80 R08: ffff8987f939bac8 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8987f5c77d00
 R13: ffff8987f5c77d08 R14: 0000000000000001 R15: ffff8987f0c29f00
 FS:  0000000000000000(0000) GS:ffff8987ffd80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000007832c004 CR4: 00000000001606e0
 Call Trace:
  <IRQ>
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ip6_finish_output2+0x369/0x590
  ip6_finish_output2+0x369/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.35+0x79/0xc0
  mld_sendpack+0x16f/0x220
  mld_ifc_timer_expire+0x195/0x2c0
  ? igmp6_timer_handler+0x70/0x70
  call_timer_fn+0x2b/0x130
  run_timer_softirq+0x3e8/0x440
  ? tick_sched_timer+0x37/0x70
  __do_softirq+0xe3/0x2f5
  irq_exit+0xf0/0x100
  smp_apic_timer_interrupt+0x6c/0x130
  apic_timer_interrupt+0xf/0x20
  </IRQ>
 RIP: 0010:native_safe_halt+0x2/0x10
 Code: 56 ff ff ff 7f f3 c3 65 48 8b 04 25 00 5c 01 00 f0 80 48 02 20 48 8b 00 a8 08 74 8b eb c1 90 90 90 90 90 90 90 90 90 90 fb f4 <c3> 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 90
 RSP: 0018:ffffa2a1c038feb8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
 RAX: ffffffffa94184f0 RBX: 0000000000000003 RCX: 0000000000000001
 RDX: 0000000000000001 RSI: 0000000000000087 RDI: 0000000000000003
 RBP: 0000000000000003 R08: 001123cfc2ba71ac R09: 0000000000000000
 R10: 0000000000000000 R11: 00000000000f4240 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  ? __sched_text_end+0x1/0x1
  default_idle+0x1c/0x140
  do_idle+0x1c4/0x280
  cpu_startup_entry+0x19/0x20
  start_secondary+0x1a7/0x200
  secondary_startup_64+0xa4/0xb0
 Modules linked in: act_skbmod veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel mbcache jbd2 snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device aesni_intel crypto_simd cryptd glue_helper snd_pcm joydev pcspkr virtio_balloon snd_timer snd i2c_piix4 soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect virtio_net sysimgblt fb_sys_fops net_failover virtio_console ttm virtio_blk failover drm crc32c_intel serio_raw ata_piix virtio_pci libata virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_skbmod_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f9a ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0f4 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-21 13:26:42 -07:00
..
Kconfig tc: Add support for configuring the taprio scheduler 2018-10-04 13:52:23 -07:00
Makefile tc: Add support for configuring the taprio scheduler 2018-10-04 13:52:23 -07:00
act_api.c net/sched: prepare TC actions to properly validate the control action 2019-03-21 13:26:41 -07:00
act_bpf.c net/sched: act_bpf: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_connmark.c net/sched: act_connmark: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_csum.c net/sched: act_csum: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_gact.c net/sched: act_gact: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_ife.c net/sched: act_ife: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_ipt.c net/sched: prepare TC actions to properly validate the control action 2019-03-21 13:26:41 -07:00
act_meta_mark.c net: remove duplicate includes 2017-12-13 13:18:46 -05:00
act_meta_skbprio.c net sched actions: change IFE modules alias names 2017-10-12 22:13:20 -07:00
act_meta_skbtcindex.c net: remove duplicate includes 2017-12-13 13:18:46 -05:00
act_mirred.c net/sched: act_mirred: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_nat.c net/sched: act_nat: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_pedit.c net/sched: act_pedit: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_police.c net/sched: act_police: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_sample.c net/sched: act_sample: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_simple.c net/sched: act_simple: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_skbedit.c net/sched: act_skbedit: validate the control action inside init() 2019-03-21 13:26:41 -07:00
act_skbmod.c net/sched: act_skbmod: validate the control action inside init() 2019-03-21 13:26:42 -07:00
act_tunnel_key.c net/sched: prepare TC actions to properly validate the control action 2019-03-21 13:26:41 -07:00
act_vlan.c net/sched: prepare TC actions to properly validate the control action 2019-03-21 13:26:41 -07:00
cls_api.c net_sched: return correct value for *notify* functions 2019-03-13 13:48:27 -07:00
cls_basic.c net_sched: initialize net pointer inside tcf_exts_init() 2019-02-22 15:26:51 -08:00
cls_bpf.c net_sched: initialize net pointer inside tcf_exts_init() 2019-02-22 15:26:51 -08:00
cls_cgroup.c net_sched: initialize net pointer inside tcf_exts_init() 2019-02-22 15:26:51 -08:00
cls_flow.c net_sched: initialize net pointer inside tcf_exts_init() 2019-02-22 15:26:51 -08:00
cls_flower.c net: sched: flower: insert new filter to idr after setting its mask 2019-03-06 10:52:16 -08:00
cls_fw.c Revert "net: sched: fw: don't set arg->stop in fw_walk() when empty" 2019-02-27 10:12:19 -08:00
cls_matchall.c net_sched: initialize net pointer inside tcf_exts_init() 2019-02-22 15:26:51 -08:00
cls_route.c net_sched: initialize net pointer inside tcf_exts_init() 2019-02-22 15:26:51 -08:00
cls_rsvp.c
cls_rsvp.h net_sched: initialize net pointer inside tcf_exts_init() 2019-02-22 15:26:51 -08:00
cls_rsvp6.c
cls_tcindex.c net_sched: initialize net pointer inside tcf_exts_init() 2019-02-22 15:26:51 -08:00
cls_u32.c net_sched: initialize net pointer inside tcf_exts_init() 2019-02-22 15:26:51 -08:00
em_canid.c
em_cmp.c
em_ipset.c netfilter: x_tables: move hook state into xt_action_param structure 2016-11-03 10:56:21 +01:00
em_ipt.c net: sched: add em_ipt ematch for calling xtables matches 2018-02-21 13:15:33 -05:00
em_meta.c net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
em_nbyte.c net: sched: em_nbyte: don't add the data offset twice 2018-01-24 14:52:40 -05:00
em_text.c
em_u32.c
ematch.c net: sched: ematch: obtain net pointer from blocks 2017-10-16 21:00:40 +01:00
sch_api.c net_sched: return correct value for *notify* functions 2019-03-13 13:48:27 -07:00
sch_atm.c net: sched: rename qdisc_destroy() to qdisc_put() 2018-09-25 20:17:35 -07:00
sch_blackhole.c net_sched: blackhole: tell upper qdisc about dropped packets 2018-06-17 08:42:33 +09:00
sch_cake.c sch_cake: Interpret fwmark parameter as a bitmask 2019-03-15 11:57:14 -07:00
sch_cbq.c net: sched: rename qdisc_destroy() to qdisc_put() 2018-09-25 20:17:35 -07:00
sch_cbs.c sched: Avoid dereferencing skb pointer after child enqueue 2019-01-15 20:12:00 -08:00
sch_choke.c net: sched: sch: add extack for change qdisc ops 2017-12-21 12:32:50 -05:00
sch_codel.c net: sched: sch: add extack for change qdisc ops 2017-12-21 12:32:50 -05:00
sch_drr.c sched: Fix detection of empty queues in child qdiscs 2019-01-15 20:12:00 -08:00
sch_dsmark.c sched: Avoid dereferencing skb pointer after child enqueue 2019-01-15 20:12:00 -08:00
sch_etf.c etf: Drop all expired packets 2018-11-16 20:39:34 -08:00
sch_fifo.c net: sched: rename qdisc_destroy() to qdisc_put() 2018-09-25 20:17:35 -07:00
sch_fq.c net_sched: sch_fq: avoid calling ktime_get_ns() if not needed 2018-11-20 09:51:32 -08:00
sch_fq_codel.c net: Add and use skb_mark_not_on_list(). 2018-09-10 10:06:54 -07:00
sch_generic.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-03-04 13:26:15 -08:00
sch_gred.c net: sched: gred: support reporting stats from offloads 2018-11-19 18:53:46 -08:00
sch_hfsc.c sched: Fix detection of empty queues in child qdiscs 2019-01-15 20:12:00 -08:00
sch_hhf.c net: Add and use skb_mark_not_on_list(). 2018-09-10 10:06:54 -07:00
sch_htb.c sched: Avoid dereferencing skb pointer after child enqueue 2019-01-15 20:12:00 -08:00
sch_ingress.c net: sched: allow ingress and clsact qdiscs to share filter blocks 2018-01-17 14:53:57 -05:00
sch_mq.c net: sched: mq: offload a graft notification 2018-11-14 08:51:28 -08:00
sch_mqprio.c net: sched: rename qdisc_destroy() to qdisc_put() 2018-09-25 20:17:35 -07:00
sch_multiq.c net: sched: rename qdisc_destroy() to qdisc_put() 2018-09-25 20:17:35 -07:00
sch_netem.c net: netem: fix skb length BUG_ON in __skb_to_sgvec 2019-02-28 10:31:31 -08:00
sch_pie.c net: sched: pie: avoid slow division in drop probability decay 2019-02-28 10:35:41 -08:00
sch_plug.c net: sched: sch: add extack for change qdisc ops 2017-12-21 12:32:50 -05:00
sch_prio.c sched: Avoid dereferencing skb pointer after child enqueue 2019-01-15 20:12:00 -08:00
sch_qfq.c sched: Fix detection of empty queues in child qdiscs 2019-01-15 20:12:00 -08:00
sch_red.c net: sched: red: notify drivers about RED's limit parameter 2018-11-14 08:51:28 -08:00
sch_sfb.c net: sched: rename qdisc_destroy() to qdisc_put() 2018-09-25 20:17:35 -07:00
sch_sfq.c net: sch: api: add extack support in tcf_block_get 2017-12-21 12:32:51 -05:00
sch_skbprio.c net/sched: add skbprio scheduler 2018-07-24 14:44:00 -07:00
sch_taprio.c tc: Add support for configuring the taprio scheduler 2018-10-04 13:52:23 -07:00
sch_tbf.c sched: Avoid dereferencing skb pointer after child enqueue 2019-01-15 20:12:00 -08:00
sch_teql.c net: sched: sch: add extack for init callback 2017-12-21 12:32:50 -05:00