audit: type=1400 audit(1519116558.544:8): avc: denied { map } for pid=4129 comm="syz-execprog" path="/root/syzkaller-shm144233282" 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-rc1+ #232 Not tainted ------------------------------------- syz-executor0/4136 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: 7 locks held by syz-executor0/4136: #0: (sb_writers#4){.+.+}, at: [<00000000c9d26389>] sb_start_write include/linux/fs.h:1547 [inline] #0: (sb_writers#4){.+.+}, at: [<00000000c9d26389>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key/1){+.+.}, at: [<00000000e78b3d28>] inode_lock_nested include/linux/fs.h:748 [inline] #1: (&type->i_mutex_dir_key/1){+.+.}, at: [<00000000e78b3d28>] do_rmdir+0x380/0x5f0 fs/namei.c:3906 #2: (&type->i_mutex_dir_key){++++}, at: [<00000000978153ed>] inode_lock include/linux/fs.h:713 [inline] #2: (&type->i_mutex_dir_key){++++}, at: [<00000000978153ed>] vfs_rmdir+0xd6/0x410 fs/namei.c:3847 #3: (jbd2_handle){.+.+}, at: [<0000000028e13203>] start_this_handle+0x488/0x1080 fs/jbd2/transaction.c:385 #4: ((&idev->mc_ifc_timer)){+.-.}, at: [<000000009d006bb4>] lockdep_copy_map include/linux/lockdep.h:178 [inline] #4: ((&idev->mc_ifc_timer)){+.-.}, at: [<000000009d006bb4>] call_timer_fn+0x1c6/0x820 kernel/time/timer.c:1316 #5: (rcu_read_lock){....}, at: [<000000007642cac5>] read_pnet include/net/net_namespace.h:280 [inline] #5: (rcu_read_lock){....}, at: [<000000007642cac5>] dev_net include/linux/netdevice.h:2056 [inline] #5: (rcu_read_lock){....}, at: [<000000007642cac5>] mld_sendpack+0x180/0xe70 net/ipv6/mcast.c:1625 #6: (rcu_read_lock){....}, at: [<00000000632df73f>] nf_hook.constprop.37+0x0/0x830 net/ipv6/mcast.c:2795 stack backtrace: CPU: 0 PID: 4136 Comm: syz-executor0 Not tainted 4.16.0-rc1+ #232 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+0xa9/0xb0 arch/x86/entry/entry_64.S:829 RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:787 [inline] RIP: 0010:lookup_bh_lru fs/buffer.c:1294 [inline] RIP: 0010:__find_get_block+0x27a/0xd90 fs/buffer.c:1306 RSP: 0018:ffff8801ba66f458 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff12 RAX: ffff8801b95b2700 RBX: 0000000000000000 RCX: ffffffff81c0e5a3 RDX: 0000000000000000 RSI: 1ffff100372b6602 RDI: ffff8801b95b2f74 RBP: ffff8801ba66f5e0 R08: 1ffff100374cde59 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8801ae2bf498 R14: ffff8801ae2bf498 R15: 0000000000029060 __getblk_gfp+0xd0/0xb80 fs/buffer.c:1332 sb_getblk include/linux/buffer_head.h:327 [inline] __ext4_get_inode_loc+0x43c/0x12e0 fs/ext4/inode.c:4520 ext4_get_inode_loc fs/ext4/inode.c:4633 [inline] ext4_reserve_inode_write+0xe1/0x230 fs/ext4/inode.c:5750 ext4_mark_inode_dirty+0x166/0xa10 fs/ext4/inode.c:5902 ext4_rmdir+0x95c/0xdc0 fs/ext4/namei.c:2974 vfs_rmdir+0x216/0x410 fs/namei.c:3858 do_rmdir+0x4c8/0x5f0 fs/namei.c:3918 SYSC_rmdir fs/namei.c:3936 [inline] SyS_rmdir+0x1a/0x20 fs/namei.c:3934 do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x26/0x9b RIP: 0033:0x453b37 RSP: 002b:00007ffcf2af3bd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 0000000000453b37 RDX: 0000000000000000 RSI: 00007ffcf2af5990 RDI: 00007ffcf2af5990 RBP: 00007ffcf2af5990 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000eac940 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000eab914