====================================================== WARNING: possible circular locking dependency detected 4.17.0-rc2+ #22 Not tainted ------------------------------------------------------ syz-executor6/9628 is trying to acquire lock: (ptrval) (sk_lock-AF_INET6){+.+.}, at: lock_sock include/net/sock.h:1469 [inline] (ptrval) (sk_lock-AF_INET6){+.+.}, 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] sctp_user_addto_chunk+0x70/0x1f0 net/sctp/sm_make_chunk.c:1550 sctp_datamsg_from_user+0x945/0x1540 net/sctp/chunk.c:290 sctp_sendmsg_to_asoc+0xd08/0x2100 net/sctp/socket.c:1951 sctp_sendmsg+0x13a8/0x1d70 net/sctp/socket.c:2123 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 ___sys_sendmsg+0x525/0x940 net/socket.c:2117 __sys_sendmmsg+0x240/0x6f0 net/socket.c:2212 __do_sys_sendmmsg net/socket.c:2241 [inline] __se_sys_sendmmsg net/socket.c:2238 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2238 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (sk_lock-AF_INET6){+.+.}: 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_INET6); lock(&mm->mmap_sem); lock(sk_lock-AF_INET6); *** DEADLOCK *** 1 lock held by syz-executor6/9628: #0: (ptrval) (&mm->mmap_sem){++++}, at: vm_mmap_pgoff+0x1a1/0x2a0 mm/util.c:355 stack backtrace: CPU: 0 PID: 9628 Comm: syz-executor6 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:00007f4b4de72c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f4b4de736d4 RCX: 0000000000455979 RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000000020ffc000 RBP: 000000000072bea0 R08: 0000000000000013 R09: 0000000000000000 R10: 0000000000020812 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fe R14: 00000000006f9070 R15: 0000000000000000 netlink: 'syz-executor2': attribute type 1 has an invalid length. netlink: 'syz-executor2': attribute type 1 has an invalid length. netlink: 'syz-executor2': attribute type 1 has an invalid length. netlink: 'syz-executor2': attribute type 1 has an invalid length. kernel msg: ebtables bug: please report to author: Wrong len argument netlink: 12 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 'syz-executor2': attribute type 21 has an invalid length. netlink: 'syz-executor2': attribute type 21 has an invalid length. netlink: 12 bytes leftover after parsing attributes in process `syz-executor3'. TCP: request_sock_TCPv6: Possible SYN flooding on port 2. Sending cookies. Check SNMP counters. netlink: 12 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 11 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 11 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. bridge0: port 3(erspan0) entered blocking state bridge0: port 3(erspan0) entered disabled state device erspan0 entered promiscuous mode bridge0: port 3(erspan0) entered blocking state bridge0: port 3(erspan0) entered forwarding state IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 netlink: 224 bytes leftover after parsing attributes in process `syz-executor3'. IPVS: Unknown mcast interface: bcsf0 IPVS: Unknown mcast interface: bcsf0 BUG: sleeping function called from invalid context at mm/slab.h:421 in_atomic(): 1, irqs_disabled(): 1, pid: 10465, name: udevd INFO: lockdep is turned off. irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] (null) hardirqs last disabled at (0): [] copy_process.part.38+0x18a8/0x6e90 kernel/fork.c:1734 softirqs last enabled at (0): [] copy_process.part.38+0x1949/0x6e90 kernel/fork.c:1737 softirqs last disabled at (0): [<0000000000000000>] (null) CPU: 0 PID: 10465 Comm: udevd 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 ___might_sleep.cold.87+0x11f/0x13a kernel/sched/core.c:6188 __might_sleep+0x95/0x190 kernel/sched/core.c:6141 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3378 [inline] __do_kmalloc mm/slab.c:3716 [inline] __kmalloc+0x2b9/0x760 mm/slab.c:3727 kmalloc_array include/linux/slab.h:631 [inline] kcalloc include/linux/slab.h:642 [inline] numa_crng_init drivers/char/random.c:798 [inline] crng_reseed+0x427/0x920 drivers/char/random.c:923 credit_entropy_bits+0x98d/0xa30 drivers/char/random.c:708 add_interrupt_randomness+0x494/0x860 drivers/char/random.c:1254 handle_irq_event_percpu+0xf9/0x1c0 kernel/irq/handle.c:191 handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206 handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:791 generic_handle_irq_desc include/linux/irqdesc.h:159 [inline] handle_irq+0x18c/0x2e7 arch/x86/kernel/irq_64.c:77 do_IRQ+0x78/0x190 arch/x86/kernel/irq.c:245 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:642 RIP: 0010:__sanitizer_cov_trace_pc+0x1/0x50 kernel/kcov.c:94 RSP: 0000:ffff880197d17500 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffda RAX: 0000000000000000 RBX: ffffea00087ddde0 RCX: ffffffff8195dd0e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffff880197d17a08 R08: ffff8801cf0c2000 R09: fffff940010fbbbb R10: fffff940010fbbbb R11: ffffea00087ddddf R12: ffffea00087ddddc R13: ffff880197d179e0 R14: ffffea00087dddc0 R15: dffffc0000000000 do_fault_around mm/memory.c:3593 [inline] do_read_fault mm/memory.c:3627 [inline] do_fault mm/memory.c:3732 [inline] handle_pte_fault mm/memory.c:3963 [inline] __handle_mm_fault+0x3268/0x4310 mm/memory.c:4087 handle_mm_fault+0x53a/0xc70 mm/memory.c:4124 __do_page_fault+0x60b/0xe40 arch/x86/mm/fault.c:1399 do_page_fault+0xee/0x8a7 arch/x86/mm/fault.c:1474 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1160 RIP: 0033:0x7f46c9e862a0 RSP: 002b:00007ffc3a754d98 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 0000000001cfa250 RCX: 0000000000000001