device gretap0 entered promiscuous mode bridge0: port 3(gretap0) entered blocking state bridge0: port 3(gretap0) entered forwarding state list_add double add: new=ffff88805e5b8958, prev=ffff88805e5b8958, next=ffff888099213540. ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:29! invalid opcode: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 0 PID: 7018 Comm: syz-executor.4 Not tainted 4.14.149 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88805e568200 task.stack: ffff88805e7a0000 RIP: 0010:__list_add_valid.cold+0x26/0x3c lib/list_debug.c:29 RSP: 0018:ffff88805e7a7a00 EFLAGS: 00010282 RAX: 0000000000000058 RBX: ffff888099213500 RCX: 0000000000000000 RDX: 000000000000d7d8 RSI: ffffffff814b3fa5 RDI: ffffed100bcf4f36 RBP: ffff88805e7a7a18 R08: 0000000000000058 R09: ffff88805e568ac8 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888099213540 R13: ffff88805e5b8958 R14: ffff88805e5b8958 R15: ffff88805e5b8958 FS: 00007fd44bae8700(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42b76e270 CR3: 0000000096617000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_add include/linux/list.h:60 [inline] list_add_tail include/linux/list.h:93 [inline] p9_fd_request+0xe3/0x2b0 net/9p/trans_fd.c:679 p9_client_rpc+0x21b/0x1180 net/9p/client.c:774 p9_client_clunk+0x89/0x150 net/9p/client.c:1507 v9fs_dentry_release+0x6d/0xd0 fs/9p/vfs_dentry.c:73 __dentry_kill+0x39a/0x580 fs/dcache.c:596 dentry_kill fs/dcache.c:632 [inline] dput.part.0+0x59f/0x750 fs/dcache.c:847 dput fs/dcache.c:811 [inline] do_one_tree+0x44/0x50 fs/dcache.c:1507 shrink_dcache_for_umount+0x67/0x140 fs/dcache.c:1521 generic_shutdown_super+0x6d/0x370 fs/super.c:431 kill_anon_super+0x3f/0x60 fs/super.c:1006 v9fs_kill_super+0x3e/0xa0 fs/9p/vfs_super.c:230 deactivate_locked_super+0x74/0xe0 fs/super.c:319 deactivate_super fs/super.c:350 [inline] deactivate_super+0x85/0xa0 fs/super.c:346 cleanup_mnt+0xb2/0x150 fs/namespace.c:1183 __cleanup_mnt+0x16/0x20 fs/namespace.c:1190 task_work_run+0x114/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459a59 RSP: 002b:00007fd44bae7c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000459a59 RDX: 0000000000000000 RSI: 000000000000000b RDI: 0000000020000140 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd44bae86d4 R13: 00000000004c9496 R14: 00000000004e0b60 R15: 00000000ffffffff Code: e9 56 ff ff ff 4c 89 e1 48 c7 c7 80 31 9d 86 e8 9f 9e 72 fe 0f 0b 48 89 f2 4c 89 e1 4c 89 ee 48 c7 c7 c0 32 9d 86 e8 88 9e 72 fe <0f> 0b 48 89 f1 48 c7 c7 40 32 9d 86 4c 89 e6 e8 74 9e 72 fe 0f RIP: __list_add_valid.cold+0x26/0x3c lib/list_debug.c:29 RSP: ffff88805e7a7a00 ---[ end trace 0a161c32fb64d680 ]---