[ INFO: possible circular locking dependency detected ] 4.9.111-g03c70fe #6 Not tainted ------------------------------------------------------- syz-executor3/11065 is trying to acquire lock: (sk_lock-AF_INET){+.+.+.}, at: [] lock_sock include/net/sock.h:1404 [inline] (sk_lock-AF_INET){+.+.+.}, at: [] do_ip_setsockopt.isra.13+0x12a/0x2b10 net/ipv4/ip_sockglue.c:636 but task is already holding lock: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756 __mutex_lock_common kernel/locking/mutex.c:521 [inline] mutex_lock_nested+0xc0/0x870 kernel/locking/mutex.c:621 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 mrtsock_destruct+0x3b/0x1e0 net/ipv4/ipmr.c:1231 ip_ra_control+0x2c2/0x420 net/ipv4/ip_sockglue.c:360 do_ip_setsockopt.isra.13+0x15ff/0x2b10 net/ipv4/ip_sockglue.c:1137 ip_setsockopt+0x3a/0xb0 net/ipv4/ip_sockglue.c:1240 raw_setsockopt+0xb7/0xd0 net/ipv4/raw.c:833 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2706 SYSC_setsockopt net/socket.c:1772 [inline] SyS_setsockopt+0x166/0x260 net/socket.c:1751 do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb check_prev_add kernel/locking/lockdep.c:1828 [inline] check_prevs_add kernel/locking/lockdep.c:1938 [inline] validate_chain kernel/locking/lockdep.c:2265 [inline] __lock_acquire+0x3019/0x4070 kernel/locking/lockdep.c:3345 lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756 lock_sock_nested+0xc6/0x120 net/core/sock.c:2511 lock_sock include/net/sock.h:1404 [inline] do_ip_setsockopt.isra.13+0x12a/0x2b10 net/ipv4/ip_sockglue.c:636 ip_setsockopt+0x3a/0xb0 net/ipv4/ip_sockglue.c:1240 udp_setsockopt+0x4a/0x90 net/ipv4/udp.c:2091 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2706 SYSC_setsockopt net/socket.c:1772 [inline] SyS_setsockopt+0x166/0x260 net/socket.c:1751 do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(sk_lock-AF_INET); lock(rtnl_mutex); lock(sk_lock-AF_INET); *** DEADLOCK *** 1 lock held by syz-executor3/11065: #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 stack backtrace: CPU: 1 PID: 11065 Comm: syz-executor3 Not tainted 4.9.111-g03c70fe #6 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801a0b6f758 ffffffff81eb2729 ffffffff855e7800 ffffffff8559d0a0 ffffffff855e7800 ffff8801c4c768e8 ffff8801c4c76000 ffff8801a0b6f7a0 ffffffff814263a4 0000000000000001 00000000c4c76000 0000000000000001 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_circular_bug.cold.51+0x1bd/0x27d kernel/locking/lockdep.c:1202 [] check_prev_add kernel/locking/lockdep.c:1828 [inline] [] check_prevs_add kernel/locking/lockdep.c:1938 [inline] [] validate_chain kernel/locking/lockdep.c:2265 [inline] [] __lock_acquire+0x3019/0x4070 kernel/locking/lockdep.c:3345 [] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756 [] lock_sock_nested+0xc6/0x120 net/core/sock.c:2511 [] lock_sock include/net/sock.h:1404 [inline] [] do_ip_setsockopt.isra.13+0x12a/0x2b10 net/ipv4/ip_sockglue.c:636 [] ip_setsockopt+0x3a/0xb0 net/ipv4/ip_sockglue.c:1240 [] udp_setsockopt+0x4a/0x90 net/ipv4/udp.c:2091 [] sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2706 [] SYSC_setsockopt net/socket.c:1772 [inline] [] SyS_setsockopt+0x166/0x260 net/socket.c:1751 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. EXT4-fs (sda1): re-mounted. Opts: data=ordered,,errors=continue TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. FAT-fs (loop1): error, fat_free: invalid cluster chain (i_pos 1041) FAT-fs (loop1): Filesystem has been set read-only blk_update_request: 730 callbacks suppressed blk_update_request: I/O error, dev loop0, sector 0 buffer_io_error: 730 callbacks suppressed Buffer I/O error on dev loop0, logical block 0, lost async page write blk_update_request: I/O error, dev loop0, sector 8 Buffer I/O error on dev loop0, logical block 1, lost async page write blk_update_request: I/O error, dev loop0, sector 16 Buffer I/O error on dev loop0, logical block 2, lost async page write blk_update_request: I/O error, dev loop0, sector 24 Buffer I/O error on dev loop0, logical block 3, lost async page write blk_update_request: I/O error, dev loop0, sector 32 Buffer I/O error on dev loop0, logical block 4, lost async page write blk_update_request: I/O error, dev loop0, sector 40 Buffer I/O error on dev loop0, logical block 5, lost async page write blk_update_request: I/O error, dev loop0, sector 48 Buffer I/O error on dev loop0, logical block 6, lost async page write blk_update_request: I/O error, dev loop0, sector 56 Buffer I/O error on dev loop0, logical block 7, lost async page write blk_update_request: I/O error, dev loop0, sector 64 Buffer I/O error on dev loop0, logical block 8, lost async page write blk_update_request: I/O error, dev loop0, sector 72 Buffer I/O error on dev loop0, logical block 9, lost async page write SELinux: unrecognized netlink message: protocol=0 nlmsg_type=11634 sclass=netlink_route_socket pig=11442 comm=syz-executor5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=11634 sclass=netlink_route_socket pig=11442 comm=syz-executor5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=11634 sclass=netlink_route_socket pig=11525 comm=syz-executor5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=11634 sclass=netlink_route_socket pig=11534 comm=syz-executor2 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=11634 sclass=netlink_route_socket pig=11537 comm=syz-executor3 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=11634 sclass=netlink_route_socket pig=11542 comm=syz-executor5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=11634 sclass=netlink_route_socket pig=11545 comm=syz-executor2 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=11634 sclass=netlink_route_socket pig=11550 comm=syz-executor3 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=11634 sclass=netlink_route_socket pig=11554 comm=syz-executor5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=11634 sclass=netlink_route_socket pig=11576 comm=syz-executor2