====================================================== WARNING: possible circular locking dependency detected 4.17.0-rc6+ #25 Not tainted ------------------------------------------------------ syz-executor2/7538 is trying to acquire lock: (ptrval) (&htab->buckets[i].lock#2){+...}, at: bpf_tcp_close+0x822/0x10b0 kernel/bpf/sockmap.c:285 but task is already holding lock: (ptrval) (clock-AF_INET6){++..}, at: bpf_tcp_close+0x241/0x10b0 kernel/bpf/sockmap.c:260 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (clock-AF_INET6){++..}: __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline] _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312 sock_hash_delete_elem+0x7c6/0xaf0 kernel/bpf/sockmap.c:2338 map_delete_elem+0x32e/0x4e0 kernel/bpf/syscall.c:815 __do_sys_bpf kernel/bpf/syscall.c:2349 [inline] __se_sys_bpf kernel/bpf/syscall.c:2317 [inline] __x64_sys_bpf+0x342/0x510 kernel/bpf/syscall.c:2317 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&htab->buckets[i].lock#2){+...}: lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168 bpf_tcp_close+0x822/0x10b0 kernel/bpf/sockmap.c:285 inet_release+0x104/0x1f0 net/ipv4/af_inet.c:427 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:459 sock_release+0x96/0x1b0 net/socket.c:594 sock_close+0x16/0x20 net/socket.c:1149 __fput+0x34d/0x890 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x1e4/0x290 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1aee/0x2730 kernel/exit.c:865 do_group_exit+0x16f/0x430 kernel/exit.c:968 get_signal+0x886/0x1960 kernel/signal.c:2482 do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810 exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(clock-AF_INET6); lock(&htab->buckets[i].lock#2); lock(clock-AF_INET6); lock(&htab->buckets[i].lock#2); *** DEADLOCK *** 2 locks held by syz-executor2/7538: #0: (ptrval) (rcu_read_lock){....}, at: bpf_tcp_close+0x0/0x10b0 kernel/bpf/sockmap.c:2106 #1: (ptrval) (clock-AF_INET6){++..}, at: bpf_tcp_close+0x241/0x10b0 kernel/bpf/sockmap.c:260 stack backtrace: CPU: 0 PID: 7538 Comm: syz-executor2 Not tainted 4.17.0-rc6+ #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 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168 bpf_tcp_close+0x822/0x10b0 kernel/bpf/sockmap.c:285 inet_release+0x104/0x1f0 net/ipv4/af_inet.c:427 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:459 sock_release+0x96/0x1b0 net/socket.c:594 sock_close+0x16/0x20 net/socket.c:1149 __fput+0x34d/0x890 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x1e4/0x290 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1aee/0x2730 kernel/exit.c:865 do_group_exit+0x16f/0x430 kernel/exit.c:968 get_signal+0x886/0x1960 kernel/signal.c:2482 do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810 exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455a09 RSP: 002b:00007f22135c4ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000072bf78 RCX: 0000000000455a09 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000072bf78 RBP: 000000000072bf78 R08: 0000000000000000 R09: 000000000072bf50 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffeb199d88f R14: 00007f22135c59c0 R15: 0000000000000001 libceph: parse_ips bad ip '[::D:e' hugetlbfs: Bad mount option: "./file0" libceph: parse_ips bad ip '[::D:e' tmpfs: Bad mount option “Q•/Ù‹«ös­º”rjµV¦ [˜”aD syz-executor4 (7664) used greatest stack depth: 12216 bytes left tmpfs: Bad mount option “Q•/Ù‹«ös­º”rjµV¦ [˜”aD FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 0 PID: 8088 Comm: syz-executor5 Not tainted 4.17.0-rc6+ #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 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 mm/slab.c:3378 [inline] __do_kmalloc mm/slab.c:3716 [inline] __kmalloc+0x2c8/0x760 mm/slab.c:3727 kmalloc include/linux/slab.h:517 [inline] kzalloc include/linux/slab.h:701 [inline] bpf_test_init.isra.8+0x98/0x100 net/bpf/test_run.c:81 bpf_prog_test_run_skb+0xfb/0xa20 net/bpf/test_run.c:103 bpf_prog_test_run+0x130/0x1a0 kernel/bpf/syscall.c:1736 __do_sys_bpf kernel/bpf/syscall.c:2375 [inline] __se_sys_bpf kernel/bpf/syscall.c:2317 [inline] __x64_sys_bpf+0x3d8/0x510 kernel/bpf/syscall.c:2317 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455a09 RSP: 002b:00007f88ef787c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f88ef7886d4 RCX: 0000000000455a09 RDX: 0000000000000028 RSI: 00000000200001c0 RDI: 000000000000000a RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 000000000000003b R14: 00000000006f4628 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 8114 Comm: syz-executor5 Not tainted 4.17.0-rc6+ #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 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 mm/slab.c:3378 [inline] kmem_cache_alloc+0x47/0x760 mm/slab.c:3552 __build_skb+0xa3/0x410 net/core/skbuff.c:281 build_skb+0x6f/0x2e0 net/core/skbuff.c:312 bpf_prog_test_run_skb+0x1a6/0xa20 net/bpf/test_run.c:122 bpf_prog_test_run+0x130/0x1a0 kernel/bpf/syscall.c:1736 __do_sys_bpf kernel/bpf/syscall.c:2375 [inline] __se_sys_bpf kernel/bpf/syscall.c:2317 [inline] __x64_sys_bpf+0x3d8/0x510 kernel/bpf/syscall.c:2317 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455a09 RSP: 002b:00007f88ef787c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f88ef7886d4 RCX: 0000000000455a09 RDX: 0000000000000028 RSI: 00000000200001c0 RDI: 000000000000000a RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 000000000000003b R14: 00000000006f4628 R15: 0000000000000001