============================================ WARNING: possible recursive locking detected 4.14.212-syzkaller #0 Not tainted -------------------------------------------- syz-executor.0/13491 is trying to acquire lock: (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: [] bond_get_stats+0xb7/0x440 drivers/net/bonding/bond_main.c:3457 but task is already holding lock: (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: [] bond_get_stats+0xb7/0x440 drivers/net/bonding/bond_main.c:3457 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&bond->stats_lock)->rlock#2/2); lock(&(&bond->stats_lock)->rlock#2/2); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by syz-executor.0/13491: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock net/core/rtnetlink.c:72 [inline] #0: (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x31d/0xb10 net/core/rtnetlink.c:4311 #1: (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: [] bond_get_stats+0xb7/0x440 drivers/net/bonding/bond_main.c:3457 #2: (rcu_read_lock){....}, at: [] bond_get_nest_level drivers/net/bonding/bond_main.c:3446 [inline] #2: (rcu_read_lock){....}, at: [] bond_get_stats+0x9b/0x440 drivers/net/bonding/bond_main.c:3457 stack backtrace: CPU: 1 PID: 13491 Comm: syz-executor.0 Not tainted 4.14.212-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+0x1b2/0x283 lib/dump_stack.c:58 print_deadlock_bug kernel/locking/lockdep.c:1800 [inline] check_deadlock kernel/locking/lockdep.c:1847 [inline] validate_chain kernel/locking/lockdep.c:2448 [inline] __lock_acquire.cold+0x180/0x97c kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 _raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:362 bond_get_stats+0xb7/0x440 drivers/net/bonding/bond_main.c:3457 dev_get_stats+0xa5/0x280 net/core/dev.c:8011 bond_get_stats+0x1da/0x440 drivers/net/bonding/bond_main.c:3463 dev_get_stats+0xa5/0x280 net/core/dev.c:8011 rtnl_fill_stats+0x48/0xa90 net/core/rtnetlink.c:1079 rtnl_fill_ifinfo+0xe16/0x3050 net/core/rtnetlink.c:1385 rtmsg_ifinfo_build_skb+0x8e/0x130 net/core/rtnetlink.c:2913 rtmsg_ifinfo_event net/core/rtnetlink.c:2943 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:2934 [inline] rtnetlink_event+0xee/0x1a0 net/core/rtnetlink.c:4360 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] netdev_features_change net/core/dev.c:1296 [inline] netdev_change_features+0x7e/0xa0 net/core/dev.c:7449 bond_compute_features+0x444/0x860 drivers/net/bonding/bond_main.c:1122 bond_slave_netdev_event drivers/net/bonding/bond_main.c:3191 [inline] bond_netdev_event+0x664/0xbd0 drivers/net/bonding/bond_main.c:3232 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] netdev_features_change net/core/dev.c:1296 [inline] netdev_change_features+0x7e/0xa0 net/core/dev.c:7449 bond_compute_features+0x444/0x860 drivers/net/bonding/bond_main.c:1122 bond_enslave+0x37e2/0x4cc0 drivers/net/bonding/bond_main.c:1757 do_set_master+0x19e/0x200 net/core/rtnetlink.c:1961 rtnl_newlink+0x134c/0x1830 net/core/rtnetlink.c:2757 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4316 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433 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: 0033:0x45e149 RSP: 002b:00007f4347207c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e149 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000006 RBP: 000000000119c110 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c0dc R13: 00007ffdb54b65af R14: 00007f43472089c0 R15: 000000000119c0dc bond1: Enslaving bridge1 as an active interface with an up link EXT4-fs (loop2): VFS: Can't find ext4 filesystem netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. batman_adv: batadv0: Adding interface: veth3 batman_adv: batadv0: The MTU of interface veth3 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface veth3 (retrying later): interface not active batman_adv: batadv0: Removing interface: veth3 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. EXT4-fs (loop2): VFS: Can't find ext4 filesystem EXT4-fs (loop1): VFS: Can't find ext4 filesystem audit: type=1804 audit(1608549165.397:128): pid=13747 uid=0 auid=0 ses=4 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir166143612/syzkaller.3jo17G/85/bus" dev="sda1" ino=16108 res=1 audit: type=1804 audit(1608549166.197:129): pid=13802 uid=0 auid=0 ses=4 op="invalid_pcr" cause="ToMToU" comm="syz-executor.0" name="/root/syzkaller-testdir166143612/syzkaller.3jo17G/85/bus" dev="sda1" ino=16108 res=1 audit: type=1804 audit(1608549166.297:130): pid=13758 uid=0 auid=0 ses=4 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir166143612/syzkaller.3jo17G/85/bus" dev="sda1" ino=16108 res=1 team0: Device geneve0 is up. Set it down before adding it as a team port IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPVS: ftp: loaded support on port[0] = 21 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready IPVS: ftp: loaded support on port[0] = 21 audit: type=1804 audit(1608549171.327:131): pid=14328 uid=0 auid=0 ses=4 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir166143612/syzkaller.3jo17G/96/bus" dev="sda1" ino=15793 res=1 audit: type=1804 audit(1608549172.287:132): pid=14402 uid=0 auid=0 ses=4 op="invalid_pcr" cause="ToMToU" comm="syz-executor.0" name="/root/syzkaller-testdir166143612/syzkaller.3jo17G/96/bus" dev="sda1" ino=15793 res=1 audit: type=1804 audit(1608549172.307:133): pid=14402 uid=0 auid=0 ses=4 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir166143612/syzkaller.3jo17G/96/bus" dev="sda1" ino=15793 res=1