incfs: ino conflict with backing FS 2
overlayfs: failed to create directory ./bus/work (errno: 22); mounting read-only
overlayfs: './file0' not a directory
general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f]
CPU: 0 PID: 6460 Comm: syz.5.1587 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:mnt_add_count fs/namespace.c:157 [inline]
RIP: 0010:mntget+0x2e/0x60 fs/namespace.c:1227
Code: 41 56 53 48 89 fb e8 a1 04 b6 ff 48 85 db 74 30 e8 97 04 b6 ff 4c 8d 73 48 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 d4 86 f0 ff 49 8b 06 65 ff 00 eb 05
RSP: 0018:ffffc900011ff640 EFLAGS: 00010206
RAX: 0000000000000009 RBX: 0000000000000001 RCX: dffffc0000000000
RDX: ffffc90001ce9000 RSI: 00000000000009cc RDI: 00000000000009cd
RBP: ffffc900011ff650 R08: ffffc900011ff6ef R09: 1ffff9200023fedd
R10: dffffc0000000000 R11: fffff5200023fede R12: 0000000000000000
R13: ffff8881410d4001 R14: 0000000000000049 R15: ffffc900011ff6e0
FS: 00007f47955956c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000009e1000 CR3: 00000001197e7000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
path_get+0x37/0x80 fs/namei.c:486
get_incfs_backing_path fs/incfs/data_mgmt.h:541 [inline]
file_open+0x1e5/0x650 fs/incfs/vfs.c:1473
do_dentry_open+0x793/0x1090 fs/open.c:819
open_with_fake_path+0x5a/0x90 fs/open.c:978
ovl_open_realfile+0x161/0x1f0 fs/overlayfs/file.c:62
ovl_open+0xdd/0x1f0 fs/overlayfs/file.c:158
do_dentry_open+0x793/0x1090 fs/open.c:819
vfs_open+0x73/0x80 fs/open.c:944
do_open fs/namei.c:3399 [inline]
path_openat+0x280f/0x31c0 fs/namei.c:3517
do_filp_open+0x1e2/0x410 fs/namei.c:3544
do_sys_openat2+0x19f/0x750 fs/open.c:1219
do_sys_open fs/open.c:1235 [inline]
__do_sys_open fs/open.c:1243 [inline]
__se_sys_open fs/open.c:1239 [inline]
__x64_sys_open+0x11c/0x140 fs/open.c:1239
do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f4796b3add9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4795595028 EFLAGS: 00000246
ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f4796db3fa0 RCX: 00007f4796b3add9
RDX: 0000000000000000 RSI: 0000000000060840 RDI: 00002000009e1000
RBP: 00007f4796bd0d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4796db4038 R14: 00007f4796db3fa0 R15: 00007ffdc4b61b88
Modules linked in:
---[ end trace f778df017a18d0da ]---
RIP: 0010:mnt_add_count fs/namespace.c:157 [inline]
RIP: 0010:mntget+0x2e/0x60 fs/namespace.c:1227
Code: 41 56 53 48 89 fb e8 a1 04 b6 ff 48 85 db 74 30 e8 97 04 b6 ff 4c 8d 73 48 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 d4 86 f0 ff 49 8b 06 65 ff 00 eb 05
RSP: 0018:ffffc900011ff640 EFLAGS: 00010206
RAX: 0000000000000009 RBX: 0000000000000001 RCX: dffffc0000000000
RDX: ffffc90001ce9000 RSI: 00000000000009cc RDI: 00000000000009cd
RBP: ffffc900011ff650 R08: ffffc900011ff6ef R09: 1ffff9200023fedd
R10: dffffc0000000000 R11: fffff5200023fede R12: 0000000000000000
R13: ffff8881410d4001 R14: 0000000000000049 R15: ffffc900011ff6e0
FS: 00007f47955956c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001197e7000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 41 56 push %r14
2: 53 push %rbx
3: 48 89 fb mov %rdi,%rbx
6: e8 a1 04 b6 ff call 0xffb604ac
b: 48 85 db test %rbx,%rbx
e: 74 30 je 0x40
10: e8 97 04 b6 ff call 0xffb604ac
15: 4c 8d 73 48 lea 0x48(%rbx),%r14
19: 4c 89 f0 mov %r14,%rax
1c: 48 c1 e8 03 shr $0x3,%rax
20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
27: fc ff df
* 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 4c 89 f7 mov %r14,%rdi
33: e8 d4 86 f0 ff call 0xfff0870c
38: 49 8b 06 mov (%r14),%rax
3b: 65 ff 00 incl %gs:(%rax)
3e: eb 05 jmp 0x45