====================================================== WARNING: possible circular locking dependency detected 4.17.0-rc2+ #22 Not tainted ------------------------------------------------------ syz-executor3/8279 is trying to acquire lock: (ptrval) (sk_lock-AF_INET){+.+.}, at: lock_sock include/net/sock.h:1469 [inline] (ptrval) (sk_lock-AF_INET){+.+.}, at: tcp_mmap+0x1c7/0x14f0 net/ipv4/tcp.c:1759 but task is already holding lock: (ptrval) (&mm->mmap_sem){++++}, at: vm_mmap_pgoff+0x1a1/0x2a0 mm/util.c:355 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&mm->mmap_sem){++++}: __might_fault+0x155/0x1e0 mm/memory.c:4555 _copy_from_iter_full+0x2fd/0xd10 lib/iov_iter.c:607 copy_from_iter_full include/linux/uio.h:124 [inline] skb_do_copy_data_nocache include/net/sock.h:1883 [inline] skb_add_data_nocache include/net/sock.h:1894 [inline] tcp_sendmsg_locked+0x2f98/0x3e10 net/ipv4/tcp.c:1316 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1446 inet_sendmsg+0x19f/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 sock_write_iter+0x35a/0x5a0 net/socket.c:908 call_write_iter include/linux/fs.h:1784 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x64d/0x960 fs/read_write.c:487 vfs_write+0x1f8/0x560 fs/read_write.c:549 ksys_write+0xf9/0x250 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe netlink: 'syz-executor1': attribute type 12 has an invalid length. -> #0 (sk_lock-AF_INET){+.+.}: lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920 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 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(sk_lock-AF_INET); lock(&mm->mmap_sem); lock(sk_lock-AF_INET); *** DEADLOCK *** 1 lock held by syz-executor3/8279: #0: (ptrval) (&mm->mmap_sem){++++}, at: vm_mmap_pgoff+0x1a1/0x2a0 mm/util.c:355 stack backtrace: CPU: 0 PID: 8279 Comm: syz-executor3 Not tainted 4.17.0-rc2+ #22 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 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 RIP: 0033:0x455979 RSP: 002b:00007f6bd726cc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f6bd726d6d4 RCX: 0000000000455979 RDX: 0000000000000004 RSI: 0000000000001000 RDI: 00000000209ec000 RBP: 000000000072bea0 R08: 0000000000000013 R09: 0000000000000000 R10: 0000000000000012 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fe R14: 00000000006f9070 R15: 0000000000000000 ieee80211 phy4: Selected rate control algorithm 'minstrel_ht' netlink: 20 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 'syz-executor1': attribute type 12 has an invalid length. ieee80211 phy5: Selected rate control algorithm 'minstrel_ht' netlink: 'syz-executor1': attribute type 12 has an invalid length. ieee80211 phy6: Selected rate control algorithm 'minstrel_ht' netlink: 'syz-executor1': attribute type 12 has an invalid length. ieee80211 phy7: Selected rate control algorithm 'minstrel_ht' netlink: 'syz-executor1': attribute type 12 has an invalid length. ieee80211 phy8: Selected rate control algorithm 'minstrel_ht' netlink: 'syz-executor1': attribute type 12 has an invalid length. xt_ipvs: protocol family 7 not supported ieee80211 phy9: Selected rate control algorithm 'minstrel_ht' kernel msg: ebtables bug: please report to author: bad policy xt_ipvs: protocol family 7 not supported IPVS: ftp: loaded support on port[0] = 21 device lo entered promiscuous mode kernel msg: ebtables bug: please report to author: entries_size too small kernel msg: ebtables bug: please report to author: entries_size too small ieee80211 phy10: Selected rate control algorithm 'minstrel_ht' dccp_invalid_packet: P.Data Offset(4) too small ieee80211 phy11: Selected rate control algorithm 'minstrel_ht' dccp_invalid_packet: P.Data Offset(4) too small ieee80211 phy12: Selected rate control algorithm 'minstrel_ht' bond0: cannot enslave bond to itself. ieee80211 phy13: Selected rate control algorithm 'minstrel_ht' bond0: cannot enslave bond to itself. mip6: mip6_rthdr_init_state: spi is not 0: 15794175 mip6: mip6_rthdr_init_state: spi is not 0: 15794175 ieee80211 phy14: Selected rate control algorithm 'minstrel_ht' ieee80211 phy15: Selected rate control algorithm 'minstrel_ht' netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. ieee80211 phy16: Selected rate control algorithm 'minstrel_ht' netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. ieee80211 phy17: Selected rate control algorithm 'minstrel_ht' ieee80211 phy18: Selected rate control algorithm 'minstrel_ht'