list_add corruption. prev is NULL. ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:24! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 395 Comm: syz-executor254 Tainted: G W 5.15.72-syzkaller-04310-g43eb03f7ce81 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 RIP: 0010:__list_add_valid+0xbc/0x100 lib/list_debug.c:23 Code: c0 74 ed 48 c7 c7 a0 c6 66 85 4c 89 fe 4c 89 e2 4c 89 f1 31 c0 e8 41 22 57 02 0f 0b 48 c7 c7 a0 c4 66 85 31 c0 e8 31 22 57 02 <0f> 0b 48 c7 c7 40 c5 66 85 31 c0 e8 21 22 57 02 0f 0b 48 c7 c7 a0 RSP: 0018:ffffc90000ae78e0 EFLAGS: 00010046 RAX: 0000000000000022 RBX: 1ffff9200015cf3d RCX: 12ffa64da8c05700 RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000 RBP: ffffc90000ae7908 R08: ffffffff81572d19 R09: 0000000000000003 R10: fffff5200015ce89 R11: 1ffff9200015ce88 R12: ffffc90000ae79e8 R13: 1ffff11020f34aac R14: ffffc90000ae79e0 R15: ffff8881079a5560 FS: 00007fa0f8103700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556eff5f8 CR3: 000000010118d000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_add include/linux/list.h:67 [inline] list_add_tail include/linux/list.h:100 [inline] __prepare_to_swait+0xad/0x140 kernel/sched/swait.c:89 do_wait_for_common kernel/sched/completion.c:82 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common+0x257/0x430 kernel/sched/completion.c:117 wait_for_completion+0x18/0x20 kernel/sched/completion.c:138 erofs_unregister_sysfs+0x5e/0x70 fs/erofs/sysfs.c:209 erofs_put_super+0x46/0xa0 fs/erofs/super.c:815 generic_shutdown_super+0x14f/0x2d0 fs/super.c:465 kill_block_super+0x80/0xe0 fs/super.c:1395 erofs_kill_sb+0x66/0x130 fs/erofs/super.c:796 deactivate_locked_super+0xb0/0x100 fs/super.c:335 get_tree_bdev+0x437/0x640 fs/super.c:1295 erofs_fc_get_tree+0x1c/0x20 fs/erofs/super.c:708 vfs_get_tree+0x88/0x290 fs/super.c:1498 do_new_mount+0x289/0xad0 fs/namespace.c:2994 path_mount+0x60b/0x1050 fs/namespace.c:3324 do_mount fs/namespace.c:3337 [inline] __do_sys_mount fs/namespace.c:3545 [inline] __se_sys_mount+0x2d2/0x3c0 fs/namespace.c:3522 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3522 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fa0f815fc9a Code: 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 98 03 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa0f8103158 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fa0f815fc9a RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fa0f8103170 RBP: 0000000000000005 R08: 00007fa0f81031b0 R09: 00007fa0f81036b8 R10: 0000000000000000 R11: 0000000000000286 R12: 00007fa0f81031b0 R13: 0000000000000002 R14: 00007fa0f8103170 R15: 0000000020000230 Modules linked in: ---[ end trace 11fa2bc6d8c10691 ]--- RIP: 0010:__list_add_valid+0xbc/0x100 lib/list_debug.c:23 Code: c0 74 ed 48 c7 c7 a0 c6 66 85 4c 89 fe 4c 89 e2 4c 89 f1 31 c0 e8 41 22 57 02 0f 0b 48 c7 c7 a0 c4 66 85 31 c0 e8 31 22 57 02 <0f> 0b 48 c7 c7 40 c5 66 85 31 c0 e8 21 22 57 02 0f 0b 48 c7 c7 a0 RSP: 0018:ffffc90000ae78e0 EFLAGS: 00010046 RAX: 0000000000000022 RBX: 1ffff9200015cf3d RCX: 12ffa64da8c05700 RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000 RBP: ffffc90000ae7908 R08: ffffffff81572d19 R09: 0000000000000003 R10: fffff5200015ce89 R11: 1ffff9200015ce88 R12: ffffc90000ae79e8 R13: 1ffff11020f34aac R14: ffffc90000ae79e0 R15: ffff8881079a5560 FS: 00007fa0f8103700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556eff5f8 CR3: 000000010118d000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400