====================================================== WARNING: possible circular locking dependency detected 4.14.226-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/27092 is trying to acquire lock: (&xt[i].mutex){+.+.}, at: [] match_revfn+0x43/0x210 net/netfilter/x_tables.c:332 but task is already holding lock: (&table[i].mutex){+.+.}, at: [] nfnl_lock net/netfilter/nfnetlink.c:61 [inline] (&table[i].mutex){+.+.}, at: [] nfnetlink_rcv_msg+0x726/0xc00 net/netfilter/nfnetlink.c:209 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&table[i].mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 nf_tables_netdev_event+0x10d/0x4d0 net/netfilter/nf_tables_netdev.c:122 notifier_call_chain+0x108/0x1a0 kernel/notifier.c:93 call_netdevice_notifiers_info net/core/dev.c:1667 [inline] call_netdevice_notifiers net/core/dev.c:1683 [inline] rollback_registered_many+0x765/0xba0 net/core/dev.c:7203 rollback_registered+0xca/0x170 net/core/dev.c:7245 unregister_netdevice_queue+0x1b4/0x360 net/core/dev.c:8266 unregister_netdevice include/linux/netdevice.h:2443 [inline] __tun_detach+0xca2/0xf60 drivers/net/tun.c:576 tun_detach drivers/net/tun.c:586 [inline] tun_chr_close+0x41/0x60 drivers/net/tun.c:2679 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa44/0x2850 kernel/exit.c:868 do_group_exit+0x100/0x2e0 kernel/exit.c:965 SYSC_exit_group kernel/exit.c:976 [inline] SyS_exit_group+0x19/0x20 kernel/exit.c:974 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (rtnl_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 unregister_netdevice_notifier+0x5e/0x2b0 net/core/dev.c:1630 tee_tg_destroy+0x5c/0xb0 net/netfilter/xt_TEE.c:123 cleanup_entry+0x232/0x310 net/ipv6/netfilter/ip6_tables.c:684 __do_replace+0x38d/0x580 net/ipv6/netfilter/ip6_tables.c:1105 do_replace net/ipv6/netfilter/ip6_tables.c:1161 [inline] do_ip6t_set_ctl+0x256/0x3b0 net/ipv6/netfilter/ip6_tables.c:1685 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x5f/0xb0 net/netfilter/nf_sockopt.c:115 ipv6_setsockopt+0xc0/0x120 net/ipv6/ipv6_sockglue.c:937 tcp_setsockopt+0x7b/0xc0 net/ipv4/tcp.c:2828 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+0x46/0xbb -> #0 (&xt[i].mutex){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 match_revfn+0x43/0x210 net/netfilter/x_tables.c:332 xt_find_revision+0x8d/0x1d0 net/netfilter/x_tables.c:380 nfnl_compat_get+0x1f7/0x870 net/netfilter/nft_compat.c:678 nfnetlink_rcv_msg+0x9bb/0xc00 net/netfilter/nfnetlink.c:214 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433 nfnetlink_rcv+0x1ab/0x1da0 net/netfilter/nfnetlink.c:515 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x6c8/0x800 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+0x46/0xbb other info that might help us debug this: Chain exists of: &xt[i].mutex --> rtnl_mutex --> &table[i].mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&table[i].mutex); lock(rtnl_mutex); lock(&table[i].mutex); lock(&xt[i].mutex); *** DEADLOCK *** 1 lock held by syz-executor.3/27092: #0: (&table[i].mutex){+.+.}, at: [] nfnl_lock net/netfilter/nfnetlink.c:61 [inline] #0: (&table[i].mutex){+.+.}, at: [] nfnetlink_rcv_msg+0x726/0xc00 net/netfilter/nfnetlink.c:209 stack backtrace: CPU: 1 PID: 27092 Comm: syz-executor.3 Not tainted 4.14.226-syzkaller #0 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+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 match_revfn+0x43/0x210 net/netfilter/x_tables.c:332 xt_find_revision+0x8d/0x1d0 net/netfilter/x_tables.c:380 nfnl_compat_get+0x1f7/0x870 net/netfilter/nft_compat.c:678 nfnetlink_rcv_msg+0x9bb/0xc00 net/netfilter/nfnetlink.c:214 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433 nfnetlink_rcv+0x1ab/0x1da0 net/netfilter/nfnetlink.c:515 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x6c8/0x800 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+0x46/0xbb RIP: 0033:0x465f69 RSP: 002b:00007fe43f287188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465f69 RDX: 000000000000c854 RSI: 0000000020000580 RDI: 0000000000000003 RBP: 00000000004bfa8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffcc0c08a0f R14: 00007fe43f287300 R15: 0000000000022000 audit: type=1804 audit(1616013786.038:58): pid=27200 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir756994254/syzkaller.Q06Ucx/1664/file0" dev="sda1" ino=15209 res=1 netlink: 1744 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 1744 bytes leftover after parsing attributes in process `syz-executor.1'. audit: type=1804 audit(1616013786.108:59): pid=27219 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir756994254/syzkaller.Q06Ucx/1664/file0" dev="sda1" ino=15209 res=1 audit: type=1804 audit(1616013787.168:60): pid=27538 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir297965247/syzkaller.yLGGje/2406/bus" dev="sda1" ino=15246 res=1 audit: type=1804 audit(1616013787.198:61): pid=27538 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.3" name="/root/syzkaller-testdir297965247/syzkaller.yLGGje/2406/bus" dev="sda1" ino=15246 res=1 audit: type=1804 audit(1616013787.448:62): pid=27554 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.3" name="/root/syzkaller-testdir297965247/syzkaller.yLGGje/2406/bus" dev="sda1" ino=15246 res=1 ucma_write: process 4078 (syz-executor.4) changed security contexts after opening file descriptor, this is not allowed. print_req_error: I/O error, dev loop4, sector 2 Buffer I/O error on dev loop4, logical block 2, async page read print_req_error: I/O error, dev loop4, sector 3 Buffer I/O error on dev loop4, logical block 3, async page read print_req_error: I/O error, dev loop4, sector 4 Buffer I/O error on dev loop4, logical block 4, async page read print_req_error: I/O error, dev loop4, sector 5 Buffer I/O error on dev loop4, logical block 5, async page read print_req_error: I/O error, dev loop4, sector 6 Buffer I/O error on dev loop4, logical block 6, async page read print_req_error: I/O error, dev loop4, sector 7 Buffer I/O error on dev loop4, logical block 7, async page read audit: type=1804 audit(1616013790.498:63): pid=28389 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir298860256/syzkaller.DO7li3/2353/bus" dev="sda1" ino=15291 res=1 audit: type=1804 audit(1616013790.518:64): pid=28389 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.1" name="/root/syzkaller-testdir298860256/syzkaller.DO7li3/2353/bus" dev="sda1" ino=15291 res=1 audit: type=1804 audit(1616013791.358:65): pid=28454 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir298860256/syzkaller.DO7li3/2354/bus" dev="sda1" ino=14145 res=1 audit: type=1804 audit(1616013791.388:66): pid=28454 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.1" name="/root/syzkaller-testdir298860256/syzkaller.DO7li3/2354/bus" dev="sda1" ino=14145 res=1 audit: type=1804 audit(1616013791.868:67): pid=28544 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir298860256/syzkaller.DO7li3/2355/bus" dev="sda1" ino=14098 res=1 audit: type=1804 audit(1616013791.868:68): pid=28544 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.1" name="/root/syzkaller-testdir298860256/syzkaller.DO7li3/2355/bus" dev="sda1" ino=14098 res=1 audit: type=1804 audit(1616013792.318:69): pid=28621 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir298860256/syzkaller.DO7li3/2356/bus" dev="sda1" ino=14274 res=1 audit: type=1804 audit(1616013792.338:70): pid=28621 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.1" name="/root/syzkaller-testdir298860256/syzkaller.DO7li3/2356/bus" dev="sda1" ino=14274 res=1 audit: type=1804 audit(1616013792.768:71): pid=28680 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir298860256/syzkaller.DO7li3/2357/bus" dev="sda1" ino=14050 res=1 audit: type=1804 audit(1616013792.768:72): pid=28680 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.1" name="/root/syzkaller-testdir298860256/syzkaller.DO7li3/2357/bus" dev="sda1" ino=14050 res=1