linux/net
Nikolay Aleksandrov 7eb9d7675c net: psample: fix skb_over_panic
We need to calculate the skb size correctly otherwise we risk triggering
skb_over_panic[1]. The issue is that data_len is added to the skb in a
nl attribute, but we don't account for its header size (nlattr 4 bytes)
and alignment. We account for it when calculating the total size in
the > PSAMPLE_MAX_PACKET_SIZE comparison correctly, but not when
allocating after that. The fix is simple - use nla_total_size() for
data_len when allocating.

To reproduce:
 $ tc qdisc add dev eth1 clsact
 $ tc filter add dev eth1 egress matchall action sample rate 1 group 1 trunc 129
 $ mausezahn eth1 -b bcast -a rand -c 1 -p 129
 < skb_over_panic BUG(), tail is 4 bytes past skb->end >

[1] Trace:
 [   50.459526][ T3480] skbuff: skb_over_panic: text:(____ptrval____) len:196 put:136 head:(____ptrval____) data:(____ptrval____) tail:0xc4 end:0xc0 dev:<NULL>
 [   50.474339][ T3480] ------------[ cut here ]------------
 [   50.481132][ T3480] kernel BUG at net/core/skbuff.c:108!
 [   50.486059][ T3480] invalid opcode: 0000 [#1] PREEMPT SMP
 [   50.489463][ T3480] CPU: 3 PID: 3480 Comm: mausezahn Not tainted 5.4.0-rc7 #108
 [   50.492844][ T3480] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
 [   50.496551][ T3480] RIP: 0010:skb_panic+0x79/0x7b
 [   50.498261][ T3480] Code: bc 00 00 00 41 57 4c 89 e6 48 c7 c7 90 29 9a 83 4c 8b 8b c0 00 00 00 50 8b 83 b8 00 00 00 50 ff b3 c8 00 00 00 e8 ae ef c0 fe <0f> 0b e8 2f df c8 fe 48 8b 55 08 44 89 f6 4c 89 e7 48 c7 c1 a0 22
 [   50.504111][ T3480] RSP: 0018:ffffc90000447a10 EFLAGS: 00010282
 [   50.505835][ T3480] RAX: 0000000000000087 RBX: ffff888039317d00 RCX: 0000000000000000
 [   50.507900][ T3480] RDX: 0000000000000000 RSI: ffffffff812716e1 RDI: 00000000ffffffff
 [   50.509820][ T3480] RBP: ffffc90000447a60 R08: 0000000000000001 R09: 0000000000000000
 [   50.511735][ T3480] R10: ffffffff81d4f940 R11: 0000000000000000 R12: ffffffff834a22b0
 [   50.513494][ T3480] R13: ffffffff82c10433 R14: 0000000000000088 R15: ffffffff838a8084
 [   50.515222][ T3480] FS:  00007f3536462700(0000) GS:ffff88803eac0000(0000) knlGS:0000000000000000
 [   50.517135][ T3480] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [   50.518583][ T3480] CR2: 0000000000442008 CR3: 000000003b222000 CR4: 00000000000006e0
 [   50.520723][ T3480] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [   50.522709][ T3480] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [   50.524450][ T3480] Call Trace:
 [   50.525214][ T3480]  skb_put.cold+0x1b/0x1b
 [   50.526171][ T3480]  psample_sample_packet+0x1d3/0x340
 [   50.527307][ T3480]  tcf_sample_act+0x178/0x250
 [   50.528339][ T3480]  tcf_action_exec+0xb1/0x190
 [   50.529354][ T3480]  mall_classify+0x67/0x90
 [   50.530332][ T3480]  tcf_classify+0x72/0x160
 [   50.531286][ T3480]  __dev_queue_xmit+0x3db/0xd50
 [   50.532327][ T3480]  dev_queue_xmit+0x18/0x20
 [   50.533299][ T3480]  packet_sendmsg+0xee7/0x2090
 [   50.534331][ T3480]  sock_sendmsg+0x54/0x70
 [   50.535271][ T3480]  __sys_sendto+0x148/0x1f0
 [   50.536252][ T3480]  ? tomoyo_file_ioctl+0x23/0x30
 [   50.537334][ T3480]  ? ksys_ioctl+0x5e/0xb0
 [   50.540068][ T3480]  __x64_sys_sendto+0x2a/0x30
 [   50.542810][ T3480]  do_syscall_64+0x73/0x1f0
 [   50.545383][ T3480]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 [   50.548477][ T3480] RIP: 0033:0x7f35357d6fb3
 [   50.551020][ T3480] Code: 48 8b 0d 18 90 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d f9 d3 20 00 00 75 13 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 eb f6 ff ff 48 89 04 24
 [   50.558547][ T3480] RSP: 002b:00007ffe0c7212c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
 [   50.561870][ T3480] RAX: ffffffffffffffda RBX: 0000000001dac010 RCX: 00007f35357d6fb3
 [   50.565142][ T3480] RDX: 0000000000000082 RSI: 0000000001dac2a2 RDI: 0000000000000003
 [   50.568469][ T3480] RBP: 00007ffe0c7212f0 R08: 00007ffe0c7212d0 R09: 0000000000000014
 [   50.571731][ T3480] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000082
 [   50.574961][ T3480] R13: 0000000001dac2a2 R14: 0000000000000001 R15: 0000000000000003
 [   50.578170][ T3480] Modules linked in: sch_ingress virtio_net
 [   50.580976][ T3480] ---[ end trace 61a515626a595af6 ]---

CC: Yotam Gigi <yotamg@mellanox.com>
CC: Jiri Pirko <jiri@mellanox.com>
CC: Jamal Hadi Salim <jhs@mojatatu.com>
CC: Simon Horman <simon.horman@netronome.com>
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
Fixes: 6ae0a62861 ("net: Introduce psample, a new genetlink channel for packet sampling")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-26 14:40:13 -08:00
..
6lowpan 6lowpan: no need to check return value of debugfs_create functions 2019-07-06 12:50:01 +02:00
9p 9p pull request for inclusion in 5.4 2019-09-27 15:10:34 -07:00
802
8021q net: remove unnecessary variables and callback 2019-10-24 14:53:49 -07:00
appletalk appletalk: enforce CAP_NET_RAW for raw sockets 2019-09-24 16:37:18 +02:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-22 16:27:24 -08:00
ax25 net: use helpers to change sk_ack_backlog 2019-11-06 16:14:48 -08:00
batman-adv batman-adv: Drop lockdep.h include for soft-interface.c 2019-11-03 08:30:58 +01:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-11-25 20:02:57 -08:00
bpf bpf: Fix memory leak on object 'data' 2019-11-18 19:32:59 -08:00
bpfilter Kbuild updates for v5.3 2019-07-12 16:03:16 -07:00
bridge bridge: implement get_link_ksettings ethtool method 2019-11-12 19:52:15 -08:00
caif Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
can can: j1939: warn if resources are still linked on destroy 2019-11-13 10:42:34 +01:00
ceph libceph: use ceph_kvmalloc() for osdmap arrays 2019-09-16 12:06:25 +02:00
core Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-11-25 20:02:57 -08:00
dcb
dccp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-09 11:04:37 -08:00
decnet net: use helpers to change sk_ack_backlog 2019-11-06 16:14:48 -08:00
dns_resolver Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
dsa net: phylink: rename mac_link_state() op to mac_pcs_get_state() 2019-11-23 16:13:39 -08:00
ethernet net: add annotations on hh->hh_len lockless accesses 2019-11-07 20:07:30 -08:00
hsr hsr: switch ->dellink() to ->ndo_uninit() 2019-07-11 14:37:45 -07:00
ieee802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
ife net: Fix Kconfig indentation 2019-09-26 08:56:17 +02:00
ipv4 net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port) 2019-11-26 13:20:46 -08:00
ipv6 net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port) 2019-11-26 13:20:46 -08:00
iucv net/af_iucv: mark expected switch fall-throughs 2019-07-29 10:26:14 -07:00
kcm kcm: disable preemption in kcm_parse_func_strparser() 2019-09-27 10:27:14 +02:00
key Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-07-08 19:48:57 -07:00
l2tp net: core: add generic lockdep keys 2019-10-24 14:53:48 -07:00
l3mdev ipv6: convert major tx path to use RT6_LOOKUP_F_DST_NOREF 2019-06-23 13:24:17 -07:00
lapb
llc net: silence data-races on sk_backlog.tail 2019-11-06 21:35:34 -08:00
mac80211 mac80211: Use Airtime-based Queue Limits (AQL) on packet dequeue 2019-11-22 13:36:25 +01:00
mac802154
mpls ipv4: mpls: fix mpls_xmit for iptunnel 2019-08-25 14:34:08 -07:00
ncsi net/ncsi: Disable global multicast filter 2019-09-19 18:04:40 -07:00
netfilter net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port) 2019-11-26 13:20:46 -08:00
netlabel netlabel: remove redundant assignment to pointer iter 2019-09-01 11:45:02 -07:00
netlink genetlink: do not parse attributes for families with zero maxattr 2019-10-13 11:20:03 -07:00
netrom net: core: add generic lockdep keys 2019-10-24 14:53:48 -07:00
nfc net: Fix Kconfig indentation, continued 2019-11-21 12:00:21 -08:00
nsh
openvswitch net: openvswitch: don't call pad_packet if not necessary 2019-11-15 12:43:27 -08:00
packet packet: fix data-race in fanout_flow_is_huge() 2019-11-08 14:06:19 -08:00
phonet net: use skb_queue_empty_lockless() in poll() handlers 2019-10-28 13:33:41 -07:00
psample net: psample: fix skb_over_panic 2019-11-26 14:40:13 -08:00
qrtr net: qrtr: Simplify 'qrtr_tun_release()' 2019-10-30 17:58:23 -07:00
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-16 21:51:42 -08:00
rfkill
rose net: use helpers to change sk_ack_backlog 2019-11-06 16:14:48 -08:00
rxrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-11-25 20:02:57 -08:00
sched Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-22 16:27:24 -08:00
sctp net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port) 2019-11-26 13:20:46 -08:00
smc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-16 21:51:42 -08:00
strparser Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-22 08:59:24 -04:00
sunrpc SUNRPC: Destroy the back channel when we destroy the host transport 2019-10-30 12:04:35 -04:00
switchdev
tipc tipc: fix link name length check 2019-11-26 10:03:12 -08:00
tls Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-22 16:27:24 -08:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
vmw_vsock vsock: avoid to assign transport if its initialization fails 2019-11-21 11:37:16 -08:00
wimax wimax: no need to check return value of debugfs_create functions 2019-08-10 15:25:47 -07:00
wireless Some relatively small changes: 2019-11-08 11:36:48 -08:00
x25 net: use helpers to change sk_ack_backlog 2019-11-06 16:14:48 -08:00
xdp xsk: Fix xsk_poll()'s return type 2019-11-24 16:58:44 -08:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-11-25 20:02:57 -08:00
compat.c
Kconfig net: Fix Kconfig indentation, continued 2019-11-21 12:00:21 -08:00
Makefile
socket.c for-5.5/io_uring-20191121 2019-11-25 10:40:27 -08:00
sysctl_net.c