Davide Caratti 4b006b0c13 net/sched: act_simple: validate the control action inside init() ... the following script: # tc qdisc add dev crash0 clsact # tc filter add dev crash0 egress matchall \ > action simple sdata hello pass index 90 # tc actions replace action simple \ > sdata world goto chain 42 index 90 cookie c1a0c1a0 # tc action show action simple 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: Simple <world> 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 800000006a6fb067 P4D 800000006a6fb067 PUD 6aed6067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 2 PID: 3241 Comm: kworker/2:0 Not tainted 5.0.0-rc4.gotochain_crash+ #536 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 Workqueue: ipv6_addrconf addrconf_dad_work 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:ffffbe6781763ad0 EFLAGS: 00010246 RAX: 000000002000002a RBX: ffff9e59bdb80e00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff9e59b4716738 RDI: ffff9e59ab12d140 RBP: ffffbe6781763b70 R08: 0000000000000234 R09: 0000000000aaaaaa R10: 0000000000000000 R11: ffff9e59b247cd50 R12: ffff9e59b112f100 R13: ffff9e59b112f108 R14: 0000000000000001 R15: ffff9e59ab12d0c0 FS: 0000000000000000(0000) GS:ffff9e59b4700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000006af92004 CR4: 00000000001606e0 Call Trace: tcf_classify+0x58/0x120 __dev_queue_xmit+0x40a/0x890 ? ndisc_next_option+0x50/0x50 ? ___neigh_create+0x4d5/0x680 ? ip6_finish_output2+0x1b5/0x590 ip6_finish_output2+0x1b5/0x590 ? ip6_output+0x68/0x110 ip6_output+0x68/0x110 ? nf_hook.constprop.28+0x79/0xc0 ndisc_send_skb+0x248/0x2e0 ndisc_send_ns+0xf8/0x200 ? addrconf_dad_work+0x389/0x4b0 addrconf_dad_work+0x389/0x4b0 ? __switch_to_asm+0x34/0x70 ? process_one_work+0x195/0x380 ? addrconf_dad_completed+0x370/0x370 process_one_work+0x195/0x380 worker_thread+0x30/0x390 ? process_one_work+0x380/0x380 kthread+0x113/0x130 ? kthread_park+0x90/0x90 ret_from_fork+0x35/0x40 Modules linked in: act_simple veth ip6table_filter ip6_tables iptable_filter binfmt_misc crct10dif_pclmul crc32_pclmul ghash_clmulni_intel ext4 snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep mbcache snd_hda_core jbd2 snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd snd_timer glue_helper snd joydev virtio_balloon pcspkr soundcore i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops virtio_net ttm net_failover virtio_console virtio_blk failover drm crc32c_intel serio_raw floppy ata_piix libata virtio_pci virtio_ring virtio dm_mirror dm_region_hash dm_log dm_mod CR2: 0000000000000000 Validating the control action within tcf_simple_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 13:26:41 -07:00
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actions	net/sched: act_simple: validate the control action inside init()	2019-03-21 13:26:41 -07:00
filters	selftests: concurrency: add test to verify parallel replace/delete	2019-02-24 12:49:59 -08:00