linux/net
Taehee Yoo 5d407b071d ip: frags: fix crash in ip_do_fragment()
A kernel crash occurrs when defragmented packet is fragmented
in ip_do_fragment().
In defragment routine, skb_orphan() is called and
skb->ip_defrag_offset is set. but skb->sk and
skb->ip_defrag_offset are same union member. so that
frag->sk is not NULL.
Hence crash occurrs in skb->sk check routine in ip_do_fragment() when
defragmented packet is fragmented.

test commands:
   %iptables -t nat -I POSTROUTING -j MASQUERADE
   %hping3 192.168.4.2 -s 1000 -p 2000 -d 60000

splat looks like:
[  261.069429] kernel BUG at net/ipv4/ip_output.c:636!
[  261.075753] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  261.083854] CPU: 1 PID: 1349 Comm: hping3 Not tainted 4.19.0-rc2+ #3
[  261.100977] RIP: 0010:ip_do_fragment+0x1613/0x2600
[  261.106945] Code: e8 e2 38 e3 fe 4c 8b 44 24 18 48 8b 74 24 08 e9 92 f6 ff ff 80 3c 02 00 0f 85 da 07 00 00 48 8b b5 d0 00 00 00 e9 25 f6 ff ff <0f> 0b 0f 0b 44 8b 54 24 58 4c 8b 4c 24 18 4c 8b 5c 24 60 4c 8b 6c
[  261.127015] RSP: 0018:ffff8801031cf2c0 EFLAGS: 00010202
[  261.134156] RAX: 1ffff1002297537b RBX: ffffed0020639e6e RCX: 0000000000000004
[  261.142156] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880114ba9bd8
[  261.150157] RBP: ffff880114ba8a40 R08: ffffed0022975395 R09: ffffed0022975395
[  261.158157] R10: 0000000000000001 R11: ffffed0022975394 R12: ffff880114ba9ca4
[  261.166159] R13: 0000000000000010 R14: ffff880114ba9bc0 R15: dffffc0000000000
[  261.174169] FS:  00007fbae2199700(0000) GS:ffff88011b400000(0000) knlGS:0000000000000000
[  261.183012] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  261.189013] CR2: 00005579244fe000 CR3: 0000000119bf4000 CR4: 00000000001006e0
[  261.198158] Call Trace:
[  261.199018]  ? dst_output+0x180/0x180
[  261.205011]  ? save_trace+0x300/0x300
[  261.209018]  ? ip_copy_metadata+0xb00/0xb00
[  261.213034]  ? sched_clock_local+0xd4/0x140
[  261.218158]  ? kill_l4proto+0x120/0x120 [nf_conntrack]
[  261.223014]  ? rt_cpu_seq_stop+0x10/0x10
[  261.227014]  ? find_held_lock+0x39/0x1c0
[  261.233008]  ip_finish_output+0x51d/0xb50
[  261.237006]  ? ip_fragment.constprop.56+0x220/0x220
[  261.243011]  ? nf_ct_l4proto_register_one+0x5b0/0x5b0 [nf_conntrack]
[  261.250152]  ? rcu_is_watching+0x77/0x120
[  261.255010]  ? nf_nat_ipv4_out+0x1e/0x2b0 [nf_nat_ipv4]
[  261.261033]  ? nf_hook_slow+0xb1/0x160
[  261.265007]  ip_output+0x1c7/0x710
[  261.269005]  ? ip_mc_output+0x13f0/0x13f0
[  261.273002]  ? __local_bh_enable_ip+0xe9/0x1b0
[  261.278152]  ? ip_fragment.constprop.56+0x220/0x220
[  261.282996]  ? nf_hook_slow+0xb1/0x160
[  261.287007]  raw_sendmsg+0x21f9/0x4420
[  261.291008]  ? dst_output+0x180/0x180
[  261.297003]  ? sched_clock_cpu+0x126/0x170
[  261.301003]  ? find_held_lock+0x39/0x1c0
[  261.306155]  ? stop_critical_timings+0x420/0x420
[  261.311004]  ? check_flags.part.36+0x450/0x450
[  261.315005]  ? _raw_spin_unlock_irq+0x29/0x40
[  261.320995]  ? _raw_spin_unlock_irq+0x29/0x40
[  261.326142]  ? cyc2ns_read_end+0x10/0x10
[  261.330139]  ? raw_bind+0x280/0x280
[  261.334138]  ? sched_clock_cpu+0x126/0x170
[  261.338995]  ? check_flags.part.36+0x450/0x450
[  261.342991]  ? __lock_acquire+0x4500/0x4500
[  261.348994]  ? inet_sendmsg+0x11c/0x500
[  261.352989]  ? dst_output+0x180/0x180
[  261.357012]  inet_sendmsg+0x11c/0x500
[ ... ]

v2:
 - clear skb->sk at reassembly routine.(Eric Dumarzet)

Fixes: fa0f527358 ("ip: use rb trees for IP frag queue.")
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-09 14:50:56 -07:00
..
6lowpan 6lowpan: iphc: reset mac_header after decompress to fix panic 2018-07-06 12:32:12 +02:00
9p Pull request for inclusion in 4.19, take two 2018-08-17 17:27:58 -07:00
802
8021q net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
appletalk Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
ax25 ax25: remove blank line at EOF 2018-07-24 14:10:42 -07:00
batman-adv Merge ra.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux 2018-07-20 21:17:12 -07:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
bpf bpf/test_run: support cgroup local storage 2018-08-03 00:47:32 +02:00
bpfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
bridge net/bridge/br_multicast: remove redundant variable "err" 2018-08-06 10:33:44 -07:00
caif net: simplify sock_poll_wait 2018-07-30 09:10:25 -07:00
can Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
ceph crush: fix using plain integer as NULL warning 2018-08-13 17:55:44 +02:00
core tcp: really ignore MSG_ZEROCOPY if no SO_ZEROCOPY 2018-09-07 23:11:06 -07:00
dcb net: dcb: Add priority-to-DSCP map getters 2018-07-27 13:17:50 -07:00
dccp Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-09 11:52:36 -07:00
decnet decnet: fix using plain integer as NULL warning 2018-08-09 14:11:24 -07:00
dns_resolver net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
dsa net: dsa: Drop GPIO includes 2018-08-27 15:24:33 -07:00
ethernet net: Convert GRO SKB handling to list_head. 2018-06-26 11:33:04 +09:00
hsr
ieee802154 net: ieee802154: 6lowpan: remove redundant pointers 'fq' and 'net' 2018-08-06 11:21:15 +02:00
ife net: sched: ife: check on metadata length 2018-04-22 21:12:00 -04:00
ipv4 ip: frags: fix crash in ip_do_fragment() 2018-09-09 14:50:56 -07:00
ipv6 ip: frags: fix crash in ip_do_fragment() 2018-09-09 14:50:56 -07:00
iucv net/iucv: declare iucv_path_table_empty() as static 2018-09-05 22:32:22 -07:00
kcm net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
key Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2018-07-27 09:33:37 -07:00
l2tp l2tp: fix unused function warning 2018-08-13 20:45:49 -07:00
l3mdev
lapb
llc Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-09 11:52:36 -07:00
mac80211 Here are quite a large number of fixes, notably: 2018-09-03 22:12:02 -07:00
mac802154 net: mac802154: tx: expand tailroom if necessary 2018-08-06 11:21:37 +02:00
mpls mpls: remove trailing whitepace 2018-07-24 14:10:42 -07:00
ncsi net/ncsi: Fixup .dumpit message flags and ID check in Netlink handler 2018-08-22 21:39:08 -07:00
netfilter treewide: convert ISO_8859-1 text comments to utf-8 2018-08-23 18:48:43 -07:00
netlabel audit: eliminate audit_enabled magic number comparison 2018-06-19 10:43:55 -04:00
netlink Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-05 13:04:31 -07:00
netrom Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
nfc net: simplify sock_poll_wait 2018-07-30 09:10:25 -07:00
nsh nsh: set mac len based on inner packet 2018-07-12 16:55:29 -07:00
openvswitch Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-02 10:55:32 -07:00
packet Revert "packet: switch kvzalloc to allocate memory" 2018-08-31 23:00:28 -07:00
phonet Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
psample
qrtr net: qrtr: Reset the node and port ID of broadcast messages 2018-07-05 20:20:03 +09:00
rds net/rds: RDS is not Radio Data System 2018-08-31 23:09:53 -07:00
rfkill Here are quite a large number of fixes, notably: 2018-09-03 22:12:02 -07:00
rose Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
rxrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
sched net_sched: properly cancel netlink dump on failure 2018-09-07 23:05:07 -07:00
sctp sctp: not traverse asoc trans list if non-ipv6 trans exists for ipv6_flowlabel 2018-09-03 21:57:54 -07:00
smc RDMA/smc: Replace ib_query_gid with rdma_get_gid_attr 2018-08-17 16:45:51 -06:00
strparser strparser: remove redundant variable 'rd_desc' 2018-08-01 10:00:06 -07:00
sunrpc NFS client updates for Linux 4.19 2018-08-23 16:03:58 -07:00
switchdev
tipc tipc: call start and done ops directly in __tipc_nl_compat_dumpit() 2018-09-06 21:49:18 -07:00
tls net/tls: Set count of SG entries if sk_alloc_sg returns -ENOSPC 2018-09-09 08:10:01 -07:00
unix af_unix: ensure POLLOUT on remote close() for connected dgram socket 2018-08-03 16:44:19 -07:00
vmw_vsock vsock: split dwork to avoid reinitializations 2018-08-07 12:39:13 -07:00
wimax wimax: remove blank lines at EOF 2018-07-24 14:10:42 -07:00
wireless Here are quite a large number of fixes, notably: 2018-09-03 22:12:02 -07:00
x25 x25: remove blank lines at EOF 2018-07-24 14:10:42 -07:00
xdp xsk: fix return value of xdp_umem_assign_dev() 2018-08-21 22:06:53 +02:00
xfrm Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-02 10:55:32 -07:00
compat.c net: avoid unnecessary sock_flag() check when enable timestamp 2018-08-06 10:42:48 -07:00
Kconfig net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
Makefile bpfilter: check compiler capability in Kconfig 2018-06-28 13:36:39 +09:00
socket.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
sysctl_net.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00