audit: type=1400 audit(1519113928.370:8): avc: denied { map } for pid=4086 comm="syz-execprog" path="/root/syzkaller-shm100432355" dev="sda1" ino=16482 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:file_t:s0 tclass=file permissive=1 IPVS: ftp: loaded support on port[0] = 21 IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready ===================================== WARNING: bad unlock balance detected! 4.16.0-rc2+ #320 Not tainted ------------------------------------- syz-executor0/4245 is trying to release lock (rcu_read_lock_bh) at: [] rcu_read_unlock_bh include/linux/rcupdate.h:722 [inline] [] hashlimit_mt_common.isra.10+0x1beb/0x2610 net/netfilter/xt_hashlimit.c:777 but there are no more locks to release! other info that might help us debug this: 3 locks held by syz-executor0/4245: #0: ((&idev->mc_ifc_timer)){+.-.}, at: [<0000000032ed0ca2>] lockdep_copy_map include/linux/lockdep.h:178 [inline] #0: ((&idev->mc_ifc_timer)){+.-.}, at: [<0000000032ed0ca2>] call_timer_fn+0x1c6/0x820 kernel/time/timer.c:1316 #1: (rcu_read_lock){....}, at: [<0000000071c537f3>] read_pnet include/net/net_namespace.h:280 [inline] #1: (rcu_read_lock){....}, at: [<0000000071c537f3>] dev_net include/linux/netdevice.h:2050 [inline] #1: (rcu_read_lock){....}, at: [<0000000071c537f3>] mld_sendpack+0x180/0xe70 net/ipv6/mcast.c:1625 #2: (rcu_read_lock){....}, at: [<0000000002d1b51f>] nf_hook.constprop.37+0x0/0x830 net/ipv6/mcast.c:2795 stack backtrace: CPU: 0 PID: 4245 Comm: syz-executor0 Not tainted 4.16.0-rc2+ #320 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_unlock_imbalance_bug+0x12f/0x140 kernel/locking/lockdep.c:3484 __lock_release kernel/locking/lockdep.c:3691 [inline] lock_release+0x6fe/0xa40 kernel/locking/lockdep.c:3939 rcu_lock_release include/linux/rcupdate.h:249 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:724 [inline] hashlimit_mt_common.isra.10+0x1c08/0x2610 net/netfilter/xt_hashlimit.c:777 hashlimit_mt+0x78/0x90 net/netfilter/xt_hashlimit.c:846 ip6t_do_table+0x98d/0x1a30 net/ipv6/netfilter/ip6_tables.c:319 ip6table_raw_hook+0x65/0x80 net/ipv6/netfilter/ip6table_raw.c:42 nf_hook_entry_hookfn include/linux/netfilter.h:120 [inline] nf_hook_slow+0xba/0x1a0 net/netfilter/core.c:483 nf_hook.constprop.37+0x3f6/0x830 include/linux/netfilter.h:243 NF_HOOK include/linux/netfilter.h:286 [inline] mld_sendpack+0x6c2/0xe70 net/ipv6/mcast.c:1658 mld_send_cr net/ipv6/mcast.c:1954 [inline] mld_ifc_timer_expire+0x3d9/0x770 net/ipv6/mcast.c:2451 call_timer_fn+0x228/0x820 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x7ee/0xb70 kernel/time/timer.c:1666 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285 invoke_softirq kernel/softirq.c:365 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:541 [inline] smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052 apic_timer_interrupt+0x8e/0xa0 arch/x86/entry/entry_64.S:796 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:777 [inline] RIP: 0010:kfree+0x106/0x260 mm/slab.c:3801 RSP: 0018:ffff8801bc5173a0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff12 RAX: 0000000000000007 RBX: ffff8801d8335500 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000282 RBP: ffff8801bc5173c0 R08: 0000000000000018 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000282 R13: ffff8801db0001c0 R14: ffffffff8221b5bf R15: 0000000000000000 selinux_sk_free_security+0x4f/0x60 security/selinux/hooks.c:4908 security_sk_free+0x48/0x80 security/security.c:1431 sk_prot_free net/core/sock.c:1504 [inline] __sk_destruct+0x60f/0x920 net/core/sock.c:1590 sk_destruct+0x47/0x80 net/core/sock.c:1598 __sk_free+0xf1/0x2b0 net/core/sock.c:1609 sk_free+0x2a/0x40 net/core/sock.c:1620 sock_put include/net/sock.h:1658 [inline] sk_common_release+0x1f0/0x2f0 net/core/sock.c:3026 rawv6_close+0x54/0x80 net/ipv6/raw.c:1226 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:427 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:435 sock_release+0x8d/0x1e0 net/socket.c:595 sock_close+0x16/0x20 net/socket.c:1149 __fput+0x327/0x7e0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ad0 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 SYSC_exit_group kernel/exit.c:979 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:977 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453da9 RSP: 002b:00007ffcc9aff008 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000018 RCX: 0000000000453da9 RDX: 0000000000000610 RSI: 0000000000735188 RDI: 0000000000000000 RBP: 00007ffcc9aff6e0 R08: 0000000000000000 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000001380