====================================================== WARNING: possible circular locking dependency detected 4.17.0-rc2+ #22 Not tainted ------------------------------------------------------ syz-executor1/9487 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] 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 ___sys_sendmsg+0x805/0x940 net/socket.c:2117 __sys_sendmsg+0x115/0x270 net/socket.c:2155 __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 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-executor1/9487: #0: (ptrval) (&mm->mmap_sem){++++}, at: vm_mmap_pgoff+0x1a1/0x2a0 mm/util.c:355 stack backtrace: CPU: 1 PID: 9487 Comm: syz-executor1 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:00007f99b959ac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f99b959b6d4 RCX: 0000000000455979 RDX: 0000000000000000 RSI: 0000000000010000 RDI: 0000000020ff0000 RBP: 000000000072bea0 R08: 0000000000000013 R09: 0000000000000000 R10: 0000000000000012 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003fe R14: 00000000006f9070 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 9493 Comm: syz-executor5 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 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.4+0xa/0x1a lib/fault-inject.c:149 __should_failslab+0x124/0x180 mm/failslab.c:32 should_failslab+0x9/0x14 mm/slab_common.c:1522 slab_pre_alloc_hook mm/slab.h:423 [inline] slab_alloc_node mm/slab.c:3299 [inline] kmem_cache_alloc_node_trace+0x26f/0x770 mm/slab.c:3661 __do_kmalloc_node mm/slab.c:3681 [inline] __kmalloc_node_track_caller+0x33/0x70 mm/slab.c:3696 __kmalloc_reserve.isra.38+0x3a/0xe0 net/core/skbuff.c:137 __alloc_skb+0x14d/0x780 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:989 [inline] __ip_append_data.isra.47+0x210d/0x29b0 net/ipv4/ip_output.c:985 ip_make_skb+0x2aa/0x340 net/ipv4/ip_output.c:1500 udp_sendmsg+0x287d/0x3450 net/ipv4/udp.c:1092 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_sendto+0x3d7/0x670 net/socket.c:1789 __do_sys_sendto net/socket.c:1801 [inline] __se_sys_sendto net/socket.c:1797 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455979 RSP: 002b:00007faf940b9c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007faf940ba6d4 RCX: 0000000000455979 RDX: 000000000000fdc7 RSI: 0000000020762fff RDI: 0000000000000013 RBP: 000000000072bea0 R08: 000000002057bff0 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 0000000000000500 R14: 00000000006fa8a0 R15: 0000000000000018 BUG: sleeping function called from invalid context at mm/slab.h:421 in_atomic(): 1, irqs_disabled(): 1, pid: 9877, 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: 9877 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:__read_once_size include/linux/compiler.h:188 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline] RIP: 0010:write_comp_data+0x22/0x70 kernel/kcov.c:122 RSP: 0018:ffff880194de6c28 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffd9 RAX: 0000000000000000 RBX: ffffc900001ed918 RCX: ffffffff81c749d4 RDX: ffff8801ce44f330 RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffff880194de6c28 R08: ffff8801d92fc040 R09: 0000000000000000 R10: ffffed0039c89e98 R11: ffff8801ce44f4c0 R12: 0000000000000040 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8801ce44f330 __sanitizer_cov_trace_const_cmp8+0x18/0x20 kernel/kcov.c:195 __d_lookup_rcu+0x1c4/0xa80 fs/dcache.c:2218 lookup_fast+0x136/0x1290 fs/namei.c:1530 walk_component+0x130/0x2550 fs/namei.c:1765 link_path_walk+0xa66/0x1520 fs/namei.c:2098 path_openat+0x246/0x4e20 fs/namei.c:3500 do_filp_open+0x249/0x350 fs/namei.c:3535 do_open_execat+0x1f6/0x650 fs/exec.c:854 open_exec+0x53/0x70 fs/exec.c:886 load_elf_binary+0x968/0x5610 fs/binfmt_elf.c:780 search_binary_handler+0x17d/0x570 fs/exec.c:1653 exec_binprm fs/exec.c:1695 [inline] do_execveat_common.isra.34+0x16ce/0x2590 fs/exec.c:1817 do_execve fs/exec.c:1862 [inline] __do_sys_execve fs/exec.c:1943 [inline] __se_sys_execve fs/exec.c:1938 [inline] __x64_sys_execve+0x8d/0xb0 fs/exec.c:1938 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f8df7e32207 RSP: 002b:00007ffe3b6c2868 EFLAGS: 00000202 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f8df7e32207 RDX: 0000000000690b20 RSI: 00007ffe3b6c2960 RDI: 00007ffe3b6c3970 RBP: 0000000000625500 R08: 0000000000000a94 R09: 0000000000000a94 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000690b20 R13: 0000000000000007 R14: 000000000067f250 R15: 0000000000000005 random: crng init done