diff options
author | Davide Caratti <dcaratti@redhat.com> | 2019-03-20 15:00:10 +0100 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2019-03-21 13:26:41 -0700 |
commit | 4b006b0c139e486773335f4c23b4d82348cfeb04 (patch) | |
tree | 697fc694ffeb4f6669bce73bb92637e8b7ba3bab /net/sched/act_simple.c | |
parent | e8c87c643ef3603c6e63bdecb67b03d794648493 (diff) | |
download | linux-4b006b0c139e486773335f4c23b4d82348cfeb04.tar.bz2 |
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: db50514f9a9c ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0f401 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/act_simple.c')
-rw-r--r-- | net/sched/act_simple.c | 52 |
1 files changed, 38 insertions, 14 deletions
diff --git a/net/sched/act_simple.c b/net/sched/act_simple.c index 4916dc3e3668..23c8ca5615e5 100644 --- a/net/sched/act_simple.c +++ b/net/sched/act_simple.c @@ -18,6 +18,7 @@ #include <linux/rtnetlink.h> #include <net/netlink.h> #include <net/pkt_sched.h> +#include <net/pkt_cls.h> #include <linux/tc_act/tc_defact.h> #include <net/tc_act/tc_defact.h> @@ -60,14 +61,26 @@ static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata) return 0; } -static void reset_policy(struct tcf_defact *d, const struct nlattr *defdata, - struct tc_defact *p) +static int reset_policy(struct tc_action *a, const struct nlattr *defdata, + struct tc_defact *p, struct tcf_proto *tp, + struct netlink_ext_ack *extack) { + struct tcf_chain *goto_ch = NULL; + struct tcf_defact *d; + int err; + + err = tcf_action_check_ctrlact(p->action, tp, &goto_ch, extack); + if (err < 0) + return err; + d = to_defact(a); spin_lock_bh(&d->tcf_lock); - d->tcf_action = p->action; + goto_ch = tcf_action_set_ctrlact(a, p->action, goto_ch); memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); nla_strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); spin_unlock_bh(&d->tcf_lock); + if (goto_ch) + tcf_chain_put_by_act(goto_ch); + return 0; } static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { @@ -82,6 +95,7 @@ static int tcf_simp_init(struct net *net, struct nlattr *nla, { struct tc_action_net *tn = net_generic(net, simp_net_id); struct nlattr *tb[TCA_DEF_MAX + 1]; + struct tcf_chain *goto_ch = NULL; struct tc_defact *parm; struct tcf_defact *d; bool exists = false; @@ -122,27 +136,37 @@ static int tcf_simp_init(struct net *net, struct nlattr *nla, } d = to_defact(*a); - ret = alloc_defdata(d, tb[TCA_DEF_DATA]); - if (ret < 0) { - tcf_idr_release(*a, bind); - return ret; - } - d->tcf_action = parm->action; + err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, + extack); + if (err < 0) + goto release_idr; + + err = alloc_defdata(d, tb[TCA_DEF_DATA]); + if (err < 0) + goto put_chain; + + tcf_action_set_ctrlact(*a, parm->action, goto_ch); ret = ACT_P_CREATED; } else { - d = to_defact(*a); - if (!ovr) { - tcf_idr_release(*a, bind); - return -EEXIST; + err = -EEXIST; + goto release_idr; } - reset_policy(d, tb[TCA_DEF_DATA], parm); + err = reset_policy(*a, tb[TCA_DEF_DATA], parm, tp, extack); + if (err) + goto release_idr; } 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_idr: + tcf_idr_release(*a, bind); + return err; } static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, |