[PATCH 4.16 39/55] nsh: fix infinite loop

Greg Kroah-Hartman
2018-05-18T08:15:35Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit af50e4ba34f4c45e92535364133d4deb5931c1c5 ]

syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48 max: 48!
48 locks held by syz-executor0/10189:
#0: (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
#1: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#1: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#2: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#2: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#3: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#3: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#4: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#4: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#5: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#5: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#6: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#6: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#7: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#7: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#8: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#8: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#9: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#9: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#10: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#10: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#11: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#11: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#12: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#12: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#13: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#13: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#14: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#14: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#15: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#15: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#16: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#16: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#17: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#17: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#18: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#18: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#19: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#19: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#20: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#20: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#21: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#21: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#22: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#22: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#23: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#23: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#24: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#24: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#25: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#25: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#26: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#26: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#27: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#27: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#28: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#28: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#29: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#29: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#30: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#30: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#31: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#31: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
#32: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#32: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#33: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#33: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#34: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#34: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#35: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#35: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#36: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#36: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#37: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#37: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#38: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#38: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#39: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#39: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#40: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#40: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#41: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#41: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#42: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#42: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#43: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#43: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#44: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#44: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#45: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#45: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#46: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#46: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
#47: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
#47: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b9/0x294 lib/dump_stack.c:113
__lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
rcu_read_lock include/linux/rcupdate.h:632 [inline]
skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
__skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
skb_gso_segment include/linux/netdevice.h:4025 [inline]
validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
qdisc_restart net/sched/sch_generic.c:399 [inline]
__qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
__dev_xmit_skb net/core/dev.c:3243 [inline]
__dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
packet_snd net/packet/af_packet.c:2951 [inline]
packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
sock_sendmsg_nosec net/socket.c:629 [inline]
sock_sendmsg+0xd5/0x120 net/socket.c:639
__sys_sendto+0x3d7/0x670 net/socket.c:1789
__do_sys_sendto net/socket.c:1801 [inline]
__se_sys_sendto net/socket.c:1797 [inline]
__x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed854584 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/nsh/nsh.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/net/nsh/nsh.c
+++ b/net/nsh/nsh.c
@@ -57,6 +57,8 @@ int nsh_pop(struct sk_buff *skb)
return -ENOMEM;
nh = (struct nshhdr *)(skb->data);
length = nsh_hdr_len(nh);
+ if (length < NSH_BASE_HDR_LEN)
+ return -EINVAL;
inner_proto = tun_p_to_eth_p(nh->np);
if (!pskb_may_pull(skb, length))
return -ENOMEM;
@@ -90,6 +92,8 @@ static struct sk_buff *nsh_gso_segment(s
if (unlikely(!pskb_may_pull(skb, NSH_BASE_HDR_LEN)))
goto out;
nsh_len = nsh_hdr_len(nsh_hdr(skb));
+ if (nsh_len < NSH_BASE_HDR_LEN)
+ goto out;
if (unlikely(!pskb_may_pull(skb, nsh_len)))
goto out;