audit: type=1400 audit(1587269330.634:8): avc: denied { execmem } for pid=6339 comm="syz-executor904" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
ip_tables: iptables: counters copy to user failed while replacing table
IPVS: ftp: loaded support on port[0] = 21
ip_tables: iptables: counters copy to user failed while replacing table
======================================================
WARNING: possible circular locking dependency detected
4.14.176-syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:2/25 is trying to acquire lock:
(&table[i].mutex){+.+.}, at: [<ffffffff852acfad>] nf_tables_netdev_event+0x10d/0x4d0 net/netfilter/nf_tables_netdev.c:122
but task is already holding lock:
(rtnl_mutex){+.+.}, at: [<ffffffff85861080>] ip6gre_exit_net+0x70/0x580 net/ipv6/ip6_gre.c:1206
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (rtnl_mutex){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893
unregister_netdevice_notifier+0x5e/0x2b0 net/core/dev.c:1634
tee_tg_destroy+0x5c/0xb0 net/netfilter/xt_TEE.c:123
cleanup_entry+0x169/0x220 net/ipv4/netfilter/ip_tables.c:666
__do_replace+0x38d/0x570 net/ipv4/netfilter/ip_tables.c:1086
do_replace net/ipv4/netfilter/ip_tables.c:1142 [inline]
do_ipt_set_ctl+0x255/0x39d net/ipv4/netfilter/ip_tables.c:1674
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x5f/0xb0 net/netfilter/nf_sockopt.c:115
ip_setsockopt net/ipv4/ip_sockglue.c:1255 [inline]
ip_setsockopt+0x94/0xb0 net/ipv4/ip_sockglue.c:1240
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2451
SYSC_setsockopt net/socket.c:1865 [inline]
SyS_setsockopt+0x110/0x1e0 net/socket.c:1844
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
-> #1 (&xt[i].mutex){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893
xt_find_revision+0x89/0x200 net/netfilter/x_tables.c:373
nfnl_compat_get+0x1f7/0x8a0 net/netfilter/nft_compat.c:678
nfnetlink_rcv_msg+0xa08/0xc00 net/netfilter/nfnetlink.c:214
netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2433
nfnetlink_rcv+0x1ab/0x1650 net/netfilter/nfnetlink.c:515
netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
netlink_unicast+0x437/0x620 net/netlink/af_netlink.c:1313
netlink_sendmsg+0x733/0xbe0 net/netlink/af_netlink.c:1878
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xc5/0x100 net/socket.c:656
___sys_sendmsg+0x70a/0x840 net/socket.c:2062
__sys_sendmsg+0xa3/0x120 net/socket.c:2096
SYSC_sendmsg net/socket.c:2107 [inline]
SyS_sendmsg+0x27/0x40 net/socket.c:2103
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
-> #0 (&table[i].mutex){+.+.}:
lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893
nf_tables_netdev_event+0x10d/0x4d0 net/netfilter/nf_tables_netdev.c:122
notifier_call_chain+0x107/0x1a0 kernel/notifier.c:93
call_netdevice_notifiers net/core/dev.c:1687 [inline]
rollback_registered_many+0x694/0xa70 net/core/dev.c:7205
unregister_netdevice_many.part.0+0x16/0x1d0 net/core/dev.c:8278
unregister_netdevice_many+0x36/0x50 net/core/dev.c:8277
ip6gre_exit_net+0x3e3/0x580 net/ipv6/ip6_gre.c:1208
ops_exit_list.isra.0+0x9d/0x140 net/core/net_namespace.c:142
cleanup_net+0x3bb/0x820 net/core/net_namespace.c:484
process_one_work+0x813/0x1540 kernel/workqueue.c:2116
worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
other info that might help us debug this:
Chain exists of:
&table[i].mutex --> &xt[i].mutex --> rtnl_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(rtnl_mutex);
lock(&xt[i].mutex);
lock(rtnl_mutex);
lock(&table[i].mutex);
*** DEADLOCK ***
4 locks held by kworker/u4:2/25:
#0: ("%s""netns"){+.+.}, at: [<ffffffff813b67f7>] work_static include/linux/workqueue.h:199 [inline]
#0: ("%s""netns"){+.+.}, at: [<ffffffff813b67f7>] set_work_data kernel/workqueue.c:619 [inline]
#0: ("%s""netns"){+.+.}, at: [<ffffffff813b67f7>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
#0: ("%s""netns"){+.+.}, at: [<ffffffff813b67f7>] process_one_work+0x727/0x1540 kernel/workqueue.c:2087
#1: (net_cleanup_work){+.+.}, at: [<ffffffff813b6831>] process_one_work+0x761/0x1540 kernel/workqueue.c:2091
#2: (net_mutex){+.+.}, at: [<ffffffff84fc9233>] cleanup_net+0x123/0x820 net/core/net_namespace.c:450
#3: (rtnl_mutex){+.+.}, at: [<ffffffff85861080>] ip6gre_exit_net+0x70/0x580 net/ipv6/ip6_gre.c:1206
stack backtrace:
CPU: 0 PID: 25 Comm: kworker/u4:2 Not tainted 4.14.176-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x13e/0x194 lib/dump_stack.c:58
print_circular_bug.isra.0.cold+0x1c4/0x282 kernel/locking/lockdep.c:1258
check_prev_add kernel/locking/lockdep.c:1901 [inline]
check_prevs_add kernel/locking/lockdep.c:2018 [inline]
validate_chain kernel/locking/lockdep.c:2460 [inline]
__lock_acquire+0x2cb3/0x4620 kernel/locking/lockdep.c:3487
lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893
nf_tables_netdev_event+0x10d/0x4d0 net/netfilter/nf_tables_netdev.c:122
notifier_call_chain+0x107/0x1a0 kernel/notifier.c:93
call_netdevice_notifiers net/core/dev.c:1687 [inline]
rollback_registered_many+0x694/0xa70 net/core/dev.c:7205
unregister_netdevice_many.part.0+0x16/0x1d0 net/core/dev.c:8278
unregister_netdevice_many+0x36/0x50 net/core/dev.c:8277
ip6gre_exit_net+0x3e3/0x580 net/ipv6/ip6_gre.c:1208
ops_exit_list.isra.0+0x9d/0x140 net/core/net_namespace.c:142
cleanup_net+0x3bb/0x820 net/core/net_namespace.c:484
process_one_work+0x813/0x1540 kernel/workqueue.c:2116
worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
IPVS: ftp: loaded support on port[0] = 21
net_ratelimit: 6 callbacks suppressed
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
IPVS: ftp: loaded support on port[0] = 21
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
net_ratelimit: 8 callbacks suppressed
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table
ip_tables: iptables: counters copy to user failed while replacing table