====================================================== WARNING: possible circular locking dependency detected 4.17.0-rc2+ #22 Not tainted ------------------------------------------------------ syz-executor2/8821 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_user+0x30/0x150 lib/usercopy.c:10 copy_from_user include/linux/uaccess.h:147 [inline] memdup_user+0x54/0xa0 mm/util.c:164 xfrm_user_policy+0x1c0/0xae0 net/xfrm/xfrm_state.c:2074 do_ipv6_setsockopt.isra.9+0x881/0x4680 net/ipv6/ipv6_sockglue.c:810 ipv6_setsockopt+0xbd/0x170 net/ipv6/ipv6_sockglue.c:922 udpv6_setsockopt+0x62/0xa0 net/ipv6/udp.c:1445 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3042 __sys_setsockopt+0x1bd/0x390 net/socket.c:1903 __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 -> #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-executor2/8821: #0: (ptrval) (&mm->mmap_sem){++++}, at: vm_mmap_pgoff+0x1a1/0x2a0 mm/util.c:355 stack backtrace: CPU: 0 PID: 8821 Comm: syz-executor2 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:00007f808cc31c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f808cc326d4 RCX: 0000000000455979 RDX: 0000000000000000 RSI: 0000000000003000 RDI: 0000000020ffc000 RBP: 000000000072bea0 R08: 0000000000000013 R09: 0000000000000000 R10: 0000000000002811 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fe R14: 00000000006f9070 R15: 0000000000000000 atomic_op (ptrval) conn xmit_atomic (null) atomic_op (ptrval) conn xmit_atomic (null) atomic_op (ptrval) conn xmit_atomic (null) atomic_op (ptrval) conn xmit_atomic (null) atomic_op (ptrval) conn xmit_atomic (null) atomic_op (ptrval) conn xmit_atomic (null) atomic_op (ptrval) conn xmit_atomic (null) atomic_op (ptrval) conn xmit_atomic (null) nla_parse: 3 callbacks suppressed netlink: 4 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor3'. IPVS: set_ctl: invalid protocol: 127 224.0.0.1:20000 ovf IPVS: set_ctl: invalid protocol: 127 224.0.0.1:20000 ovf netlink: 4 bytes leftover after parsing attributes in process `syz-executor3'. IPVS: set_ctl: invalid protocol: 127 224.0.0.1:20000 ovf IPVS: set_ctl: invalid protocol: 127 224.0.0.1:20000 ovf netlink: 4 bytes leftover after parsing attributes in process `syz-executor3'. IPVS: set_ctl: invalid protocol: 127 224.0.0.1:20000 ovf IPVS: set_ctl: invalid protocol: 127 224.0.0.1:20000 ovf BUG: sleeping function called from invalid context at mm/slab.h:421 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/0 INFO: lockdep is turned off. irq event stamp: 974070 hardirqs last enabled at (974069): [] tick_nohz_idle_exit+0x154/0x290 kernel/time/tick-sched.c:1167 hardirqs last disabled at (974070): [] __schedule+0x22d/0x1e30 kernel/sched/core.c:3417 softirqs last enabled at (974058): [] __do_softirq+0x778/0xaf5 kernel/softirq.c:311 softirqs last disabled at (974037): [] invoke_softirq kernel/softirq.c:365 [inline] softirqs last disabled at (974037): [] irq_exit+0x1d1/0x200 kernel/softirq.c:405 CPU: 0 PID: 0 Comm: swapper/0 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:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0000:ffffffff88c07bc0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffffda RAX: dffffc0000000000 RBX: 1ffffffff1180f7b RCX: ffffffff81643f32 RDX: 1ffffffff11a3160 RSI: 0000000000000004 RDI: ffffffff88d18b00 RBP: ffffffff88c07bc0 R08: ffffed003b5c46c3 R09: ffffed003b5c46c2 R10: ffffed003b5c46c2 R11: ffff8801dae23613 R12: 0000000000000000 R13: ffffffff88c07c78 R14: ffffffff897c17a0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xc2/0x440 arch/x86/kernel/process.c:354 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:345 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x395/0x560 kernel/sched/idle.c:262 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:368 rest_init+0xe1/0xe4 init/main.c:441 start_kernel+0x906/0x92d init/main.c:737 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:445 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:426 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242 random: crng init done