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authorDavide Caratti <dcaratti@redhat.com>2019-03-20 15:00:10 +0100
committerDavid S. Miller <davem@davemloft.net>2019-03-21 13:26:41 -0700
commit4b006b0c139e486773335f4c23b4d82348cfeb04 (patch)
tree697fc694ffeb4f6669bce73bb92637e8b7ba3bab /net/sched/act_simple.c
parentnet/sched: act_sample: validate the control action inside init() (diff)
downloadlinux-dev-4b006b0c139e486773335f4c23b4d82348cfeb04.tar.xz
linux-dev-4b006b0c139e486773335f4c23b4d82348cfeb04.zip
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.c52
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,