====================================================== WARNING: possible circular locking dependency detected 4.17.0-rc2+ #25 Not tainted ------------------------------------------------------ syz-executor2/6670 is trying to acquire lock: (ptrval) (&mm->mmap_sem){++++}, at: __might_fault+0xfb/0x1e0 mm/memory.c:4554 but task is already holding lock: (ptrval) (sk_lock-AF_INET6){+.+.}, at: lock_sock include/net/sock.h:1469 [inline] (ptrval) (sk_lock-AF_INET6){+.+.}, at: sock_setsockopt+0x19c/0x1fe0 net/core/sock.c:717 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sk_lock-AF_INET6){+.+.}: lock_sock_nested+0xd0/0x120 net/core/sock.c:2844 lock_sock include/net/sock.h:1469 [inline] tcp_mmap+0x1c7/0x14f0 net/ipv4/tcp.c:1759 sock_mmap+0x8e/0xc0 net/socket.c:1144 call_mmap include/linux/fs.h:1789 [inline] mmap_region+0xd13/0x1820 mm/mmap.c:1723 do_mmap+0xc79/0x11d0 mm/mmap.c:1494 do_mmap_pgoff include/linux/mm.h:2237 [inline] vm_mmap_pgoff+0x1fb/0x2a0 mm/util.c:357 ksys_mmap_pgoff+0x4c9/0x640 mm/mmap.c:1544 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&mm->mmap_sem){++++}: lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920 __might_fault+0x155/0x1e0 mm/memory.c:4555 _copy_from_user+0x30/0x150 lib/usercopy.c:10 copy_from_user include/linux/uaccess.h:147 [inline] sock_setsockopt+0x1168/0x1fe0 net/core/sock.c:928 __sys_setsockopt+0x2df/0x390 net/socket.c:1899 __do_sys_setsockopt net/socket.c:1914 [inline] __se_sys_setsockopt net/socket.c:1911 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1911 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sk_lock-AF_INET6); lock(&mm->mmap_sem); lock(sk_lock-AF_INET6); lock(&mm->mmap_sem); *** DEADLOCK *** 1 lock held by syz-executor2/6670: #0: (ptrval) (sk_lock-AF_INET6){+.+.}, at: lock_sock include/net/sock.h:1469 [inline] #0: (ptrval) (sk_lock-AF_INET6){+.+.}, at: sock_setsockopt+0x19c/0x1fe0 net/core/sock.c:717 stack backtrace: CPU: 1 PID: 6670 Comm: syz-executor2 Not tainted 4.17.0-rc2+ #25 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 print_circular_bug.isra.36.cold.54+0x1bd/0x27d kernel/locking/lockdep.c:1223 check_prev_add kernel/locking/lockdep.c:1863 [inline] check_prevs_add kernel/locking/lockdep.c:1976 [inline] validate_chain kernel/locking/lockdep.c:2417 [inline] __lock_acquire+0x343e/0x5140 kernel/locking/lockdep.c:3431 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920 __might_fault+0x155/0x1e0 mm/memory.c:4555 _copy_from_user+0x30/0x150 lib/usercopy.c:10 copy_from_user include/linux/uaccess.h:147 [inline] sock_setsockopt+0x1168/0x1fe0 net/core/sock.c:928 __sys_setsockopt+0x2df/0x390 net/socket.c:1899 __do_sys_setsockopt net/socket.c:1914 [inline] __se_sys_setsockopt net/socket.c:1911 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1911 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455979 RSP: 002b:00007f8b97164c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f8b971656d4 RCX: 0000000000455979 RDX: 000000000000001a RSI: 0000000000000001 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000010 R09: 0000000000000000 R10: 0000000020efe000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000578 R14: 00000000006fc3e0 R15: 0000000000000000 IPVS: set_ctl: invalid protocol: 135 127.0.0.1:20004 fo netlink: 40 bytes leftover after parsing attributes in process `syz-executor1'. IPVS: set_ctl: invalid protocol: 135 127.0.0.1:20004 fo netlink: 40 bytes leftover after parsing attributes in process `syz-executor1'. TCP: request_sock_TCP: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_team: link becomes ready netlink: 32 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 32 bytes leftover after parsing attributes in process `syz-executor1'. IPVS: set_ctl: invalid protocol: 43 255.255.255.255:20003 lblcr IPVS: set_ctl: invalid protocol: 143 172.20.20.170:20004 sed IPVS: set_ctl: invalid protocol: 43 255.255.255.255:20003 lblcr IPVS: set_ctl: invalid protocol: 143 172.20.20.170:20004 sed netlink: 'syz-executor5': attribute type 21 has an invalid length. dccp_close: ABORT with 1 bytes unread can: request_module (can-proto-0) failed. can: request_module (can-proto-0) failed. kernel msg: ebtables bug: please report to author: EBT_ENTRY_OR_ENTRIES shouldn't be set in distinguisher kernel msg: ebtables bug: please report to author: EBT_ENTRY_OR_ENTRIES shouldn't be set in distinguisher kernel msg: ebtables bug: please report to author: EBT_ENTRY_OR_ENTRIES shouldn't be set in distinguisher kernel msg: ebtables bug: please report to author: EBT_ENTRY_OR_ENTRIES shouldn't be set in distinguisher netlink: 'syz-executor0': attribute type 4 has an invalid length. netlink: 28 bytes leftover after parsing attributes in process `syz-executor0'. sit0: Invalid MTU 99 requested, hw min 1280 netlink: 'syz-executor0': attribute type 4 has an invalid length. netlink: 28 bytes leftover after parsing attributes in process `syz-executor0'. sit0: Invalid MTU 99 requested, hw min 1280 A link change request failed with some changes committed already. Interface vcan0 may have been left with an inconsistent configuration, please check. A link change request failed with some changes committed already. Interface vcan0 may have been left with an inconsistent configuration, please check. netlink: 4 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor6'. sock: sock_set_timeout: `syz-executor6' (pid 7458) tries to set negative timeout netlink: 12 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor0'. syz-executor5 uses obsolete (PF_INET,SOCK_PACKET) TCP: request_sock_TCP: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters.