------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 13508 at lib/refcount.c:187 refcount_sub_and_test+0x2e7/0x350 lib/refcount.c:187 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 13508 Comm: syz-executor2 Not tainted 4.18.0-rc3+ #48 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+0x1c9/0x2b4 lib/dump_stack.c:113 panic+0x238/0x4e7 kernel/panic.c:184 __warn.cold.8+0x163/0x1ba kernel/panic.c:536 report_bug+0x252/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992 RIP: 0010:refcount_sub_and_test+0x2e7/0x350 lib/refcount.c:187 Code: 89 de e8 ec c0 1c fe 84 db 74 07 31 db e9 46 ff ff ff e8 0c c0 1c fe 48 c7 c7 a0 41 1a 88 c6 05 cd 82 3a 06 01 e8 d9 e2 e7 fd <0f> 0b 31 db e9 25 ff ff ff 48 8b bd 28 ff ff ff 89 85 34 ff ff ff RSP: 0018:ffff880196017780 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90008e4c000 RDX: 0000000000003345 RSI: ffffffff81631851 RDI: ffff880196017458 RBP: ffff880196017868 R08: ffff8801ad032780 R09: fffffbfff11f1220 R10: fffffbfff11f1220 R11: ffffffff88f89103 R12: 00000000ffffffff R13: ffff880196017840 R14: 0000000000000001 R15: 0000000000000000 refcount_dec_and_test+0x1a/0x20 lib/refcount.c:212 smap_release_sock+0x76/0x320 kernel/bpf/sockmap.c:1453 sock_hash_ctx_update_elem.isra.27+0x8cb/0x1690 kernel/bpf/sockmap.c:2396 sock_hash_update_elem+0x157/0x2f0 kernel/bpf/sockmap.c:2418 map_update_elem+0x5c4/0xc90 kernel/bpf/syscall.c:765 __do_sys_bpf kernel/bpf/syscall.c:2296 [inline] __se_sys_bpf kernel/bpf/syscall.c:2267 [inline] __x64_sys_bpf+0x32d/0x510 kernel/bpf/syscall.c:2267 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455e29 Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fdd2bda0c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fdd2bda16d4 RCX: 0000000000455e29 RDX: 0000000000000020 RSI: 0000000020000180 RDI: 0000000000000002 RBP: 000000000072bf48 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004bbb6c R14: 00000000004c8db0 R15: 0000000000000001 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..