incfs: ino conflict with backing FS 2 overlayfs: failed to create directory ./bus/work (errno: 22); mounting read-only general protection fault, probably for non-canonical address 0xdffffc000000000a: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057] CPU: 0 PID: 3536 Comm: syz.4.697 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:mnt_add_count fs/namespace.c:179 [inline] RIP: 0010:mntget+0x2e/0x60 fs/namespace.c:1296 Code: 41 56 53 48 89 fb e8 41 95 a9 ff 48 85 db 74 30 e8 37 95 a9 ff 4c 8d 73 50 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 c4 1f ef ff 49 8b 06 65 ff 00 eb 05 RSP: 0018:ffffc9000e5b7400 EFLAGS: 00010206 RAX: 000000000000000a RBX: 0000000000000001 RCX: dffffc0000000000 RDX: ffffc90003a13000 RSI: 00000000000022dd RDI: 00000000000022de RBP: ffffc9000e5b7410 R08: ffffc9000e5b74af R09: 1ffff92001cb6e95 R10: dffffc0000000000 R11: fffff52001cb6e96 R12: 0000000000000000 R13: ffffc9000e5b7401 R14: 0000000000000051 R15: ffffc9000e5b74a0 FS: 00007f50b0f566c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fca0c26e000 CR3: 000000013532d000 CR4: 00000000003526b0 Call Trace: path_get+0x37/0x80 fs/namei.c:547 get_incfs_backing_path fs/incfs/data_mgmt.h:541 [inline] file_open+0x1e3/0x680 fs/incfs/vfs.c:1496 do_dentry_open+0x885/0x11f0 fs/open.c:884 open_with_fake_path+0x5a/0x90 fs/open.c:1093 ovl_open_realfile+0x20c/0x290 fs/overlayfs/file.c:66 ovl_open+0x168/0x2e0 fs/overlayfs/file.c:163 do_dentry_open+0x885/0x11f0 fs/open.c:884 vfs_open+0x73/0x80 fs/open.c:1017 do_open fs/namei.c:3633 [inline] path_openat+0x2699/0x2f30 fs/namei.c:3790 do_filp_open+0x1ee/0x420 fs/namei.c:3817 do_open_execat+0x14a/0xaa0 fs/exec.c:931 bprm_execve+0x40f/0x1390 fs/exec.c:1853 do_execveat_common+0x8e3/0xaa0 fs/exec.c:1983 do_execve fs/exec.c:2057 [inline] __do_sys_execve fs/exec.c:2133 [inline] __se_sys_execve fs/exec.c:2128 [inline] __x64_sys_execve+0x92/0xb0 fs/exec.c:2128 x64_sys_call+0x98/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:60 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f50aff9de99 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:00007f50b0f56028 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00007f50b0225fa0 RCX: 00007f50aff9de99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000040 RBP: 00007f50b0033eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f50b0226038 R14: 00007f50b0225fa0 R15: 00007ffd4c6fb838 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:mnt_add_count fs/namespace.c:179 [inline] RIP: 0010:mntget+0x2e/0x60 fs/namespace.c:1296 Code: 41 56 53 48 89 fb e8 41 95 a9 ff 48 85 db 74 30 e8 37 95 a9 ff 4c 8d 73 50 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 c4 1f ef ff 49 8b 06 65 ff 00 eb 05 RSP: 0018:ffffc9000e5b7400 EFLAGS: 00010206 RAX: 000000000000000a RBX: 0000000000000001 RCX: dffffc0000000000 RDX: ffffc90003a13000 RSI: 00000000000022dd RDI: 00000000000022de RBP: ffffc9000e5b7410 R08: ffffc9000e5b74af R09: 1ffff92001cb6e95 R10: dffffc0000000000 R11: fffff52001cb6e96 R12: 0000000000000000 R13: ffffc9000e5b7401 R14: 0000000000000051 R15: ffffc9000e5b74a0 FS: 00007f50b0f566c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fca0c26e000 CR3: 000000013532d000 CR4: 00000000003526b0 ---------------- Code disassembly (best guess): 0: 41 56 push %r14 2: 53 push %rbx 3: 48 89 fb mov %rdi,%rbx 6: e8 41 95 a9 ff call 0xffa9954c b: 48 85 db test %rbx,%rbx e: 74 30 je 0x40 10: e8 37 95 a9 ff call 0xffa9954c 15: 4c 8d 73 50 lea 0x50(%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 c4 1f ef ff call 0xffef1ffc 38: 49 8b 06 mov (%r14),%rax 3b: 65 ff 00 incl %gs:(%rax) 3e: eb 05 jmp 0x45