From e5fdabacbffc5d321bf9f51410fe0db0834606eb Mon Sep 17 00:00:00 2001 From: Davide Caratti Date: Wed, 20 Mar 2019 15:00:13 +0100 Subject: net/sched: act_tunnel_key: validate the control action inside init() the following script: # tc qdisc add dev crash0 clsact # tc filter add dev crash0 egress matchall \ > action tunnel_key set src_ip 10.10.10.1 dst_ip 20.20.2 dst_port 3128 \ > nocsum id 1 pass index 90 # tc actions replace action tunnel_key \ > set src_ip 10.10.10.1 dst_ip 20.20.2 dst_port 3128 nocsum id 1 \ > goto chain 42 index 90 cookie c1a0c1a0 # tc actions show action tunnel_key had the following output: Error: Failed to init TC action chain. We have an error talking to the kernel total acts 1 action order 0: tunnel_key set src_ip 10.10.10.1 dst_ip 20.20.2.0 key_id 1 dst_port 3128 nocsum goto chain 42 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 800000002aba4067 P4D 800000002aba4067 PUD 795f9067 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:ffff9346bdb83be0 EFLAGS: 00010246 RAX: 000000002000002a RBX: ffff9346bb795c00 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffff93466c881700 RDI: 0000000000000246 RBP: ffff9346bdb83c80 R08: ffff9346b3e1e0c8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9346b978f000 R13: ffff9346b978f008 R14: 0000000000000001 R15: ffff93466dceeb40 FS: 0000000000000000(0000) GS:ffff9346bdb80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007a6c2002 CR4: 00000000001606e0 Call Trace: 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 RIP: 0010:native_safe_halt+0x2/0x10 Code: 55 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 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 90 RSP: 0018:ffffa48a8038feb8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffffaa8184f0 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000087 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0011251c6fcfac49 R09: ffff9346b995be00 R10: ffffa48a805e7ce8 R11: 00000000024c38dd 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_tunnel_key veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 crct10dif_pclmul crc32_pclmul snd_hda_codec_generic ghash_clmulni_intel mbcache snd_hda_intel jbd2 snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd glue_helper joydev snd_timer snd pcspkr virtio_balloon soundcore i2c_piix4 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 ttm net_failover virtio_console virtio_blk failover drm serio_raw crc32c_intel ata_piix virtio_pci floppy virtio_ring libata virtio dm_mirror dm_region_hash dm_log dm_mod CR2: 0000000000000000 Validating the control action within tcf_tunnel_key_init() proved to fix the above issue. A TDC selftest is added to verify the correct behavior. Fixes: db50514f9a9c ("net: sched: add termination action to allow goto chain") Fixes: 97763dc0f401 ("net_sched: reject unknown tcfa_action values") Signed-off-by: Davide Caratti Signed-off-by: David S. Miller --- net/sched/act_tunnel_key.c | 18 ++++++++++++++-- .../tc-testing/tc-tests/actions/tunnel_key.json | 25 ++++++++++++++++++++++ 2 files changed, 41 insertions(+), 2 deletions(-) diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c index fc295d91559a..d5aaf90a3971 100644 --- a/net/sched/act_tunnel_key.c +++ b/net/sched/act_tunnel_key.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -217,6 +218,7 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla, struct nlattr *tb[TCA_TUNNEL_KEY_MAX + 1]; struct tcf_tunnel_key_params *params_new; struct metadata_dst *metadata = NULL; + struct tcf_chain *goto_ch = NULL; struct tc_tunnel_key *parm; struct tcf_tunnel_key *t; bool exists = false; @@ -360,6 +362,12 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla, goto release_tun_meta; } + err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); + if (err < 0) { + ret = err; + exists = true; + goto release_tun_meta; + } t = to_tunnel_key(*a); params_new = kzalloc(sizeof(*params_new), GFP_KERNEL); @@ -367,23 +375,29 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla, NL_SET_ERR_MSG(extack, "Cannot allocate tunnel key parameters"); ret = -ENOMEM; exists = true; - goto release_tun_meta; + goto put_chain; } params_new->tcft_action = parm->t_action; params_new->tcft_enc_metadata = metadata; spin_lock_bh(&t->tcf_lock); - t->tcf_action = parm->action; + goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); rcu_swap_protected(t->params, params_new, lockdep_is_held(&t->tcf_lock)); spin_unlock_bh(&t->tcf_lock); tunnel_key_release_params(params_new); + if (goto_ch) + tcf_chain_put_by_act(goto_ch); if (ret == ACT_P_CREATED) tcf_idr_insert(tn, *a); return ret; +put_chain: + if (goto_ch) + tcf_chain_put_by_act(goto_ch); + release_tun_meta: if (metadata) dst_release(&metadata->dst); diff --git a/tools/testing/selftests/tc-testing/tc-tests/actions/tunnel_key.json b/tools/testing/selftests/tc-testing/tc-tests/actions/tunnel_key.json index e7e15a7336b6..28453a445fdb 100644 --- a/tools/testing/selftests/tc-testing/tc-tests/actions/tunnel_key.json +++ b/tools/testing/selftests/tc-testing/tc-tests/actions/tunnel_key.json @@ -884,5 +884,30 @@ "teardown": [ "$TC actions flush action tunnel_key" ] + }, + { + "id": "8242", + "name": "Replace tunnel_key set action with invalid goto chain", + "category": [ + "actions", + "tunnel_key" + ], + "setup": [ + [ + "$TC actions flush action tunnel_key", + 0, + 1, + 255 + ], + "$TC actions add action tunnel_key set src_ip 10.10.10.1 dst_ip 20.20.20.2 dst_port 3128 nocsum id 1 pass index 90" + ], + "cmdUnderTest": "$TC actions replace action tunnel_key set src_ip 10.10.10.2 dst_ip 20.20.20.1 dst_port 3129 id 2 csum goto chain 42 index 90 cookie c1a0c1a0", + "expExitCode": "255", + "verifyCmd": "$TC actions get action tunnel_key index 90", + "matchPattern": "action order [0-9]+: tunnel_key.*set.*src_ip 10.10.10.1.*dst_ip 20.20.20.2.*key_id 1.*dst_port 3128.*csum pass.*index 90 ref", + "matchCount": "1", + "teardown": [ + "$TC actions flush action tunnel_key" + ] } ] -- cgit v1.2.3-59-g8ed1b