Davide Caratti 0da2dbd602 net/sched: act_gact: validate the control action inside init() ... the following script: # tc qdisc add dev crash0 clsact # tc filter add dev crash0 egress matchall \ > action gact pass index 90 # tc actions replace action gact \ > goto chain 42 index 90 cookie c1a0c1a0 # tc actions show action gact 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: gact action goto chain 42 random type none pass val 0 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 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.0.0-rc4.gotochain_crash+ #533 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:ffff8c2434703be0 EFLAGS: 00010246 RAX: 000000002000002a RBX: ffff8c23ed6d7e00 RCX: 000000000000005a RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8c23ed6d7e00 RBP: ffff8c2434703c80 R08: ffff8c243b639ac8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8c2429e68b00 R13: ffff8c2429e68b08 R14: 0000000000000001 R15: ffff8c2429c5a480 FS: 0000000000000000(0000) GS:ffff8c2434700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000002dc0e005 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: 74 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:ffff9c8640387eb8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff8b2184f0 RBX: 0000000000000002 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000087 RDI: 0000000000000002 RBP: 0000000000000002 R08: 000eb57882b36cc3 R09: 0000000000000020 R10: 0000000000000004 R11: 0000000000000000 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_gact act_bpf veth ip6table_filter ip6_tables iptable_filter binfmt_misc crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec_generic ext4 snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core mbcache jbd2 snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd glue_helper virtio_balloon joydev pcspkr 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 virtio_net sysfillrect net_failover virtio_blk sysimgblt fb_sys_fops virtio_console ttm failover drm crc32c_intel serio_raw ata_piix libata floppy virtio_pci virtio_ring virtio dm_mirror dm_region_hash dm_log dm_mod [last unloaded: act_bpf] CR2: 0000000000000000 Validating the control action within tcf_gact_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
..
fault-injection	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
ktest	These commits have either been sitting in my INBOX or have been	2018-04-11 16:42:27 -07:00
nvdimm	nfit_test: fix security state pull for nvdimm security nfit_test	2019-01-21 09:56:29 -08:00
radix-tree	radix tree: Don't return retry entries from lookup	2018-12-06 08:26:16 -05:00
scatterlist	tools/testing/scatterlist: Test new __sg_alloc_table_from_pages	2017-09-07 10:54:40 +01:00
selftests	net/sched: act_gact: validate the control action inside init()	2019-03-21 13:26:41 -07:00
vsock	VSOCK: add tools/testing/vsock/vsock_diag_test	2017-10-05 18:44:17 -07:00