EXT4-fs (loop3): mounted filesystem without journal. Opts: nogrpid,barrier,debug_want_extra_isize=0x0000000000000068,errors=remount-ro,nombcache,quota,nojournal_checksum, incfs: ino conflict with backing FS 2 overlayfs: failed to create directory ./bus/work (errno: 22); mounting read-only overlayfs: fs on '.' does not support file handles, falling back to index=off,nfs_export=off. fuse: Bad value for 'group_id' 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: 625 Comm: syz.3.81 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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 61 1c b6 ff 48 85 db 74 30 e8 57 1c 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 c4 91 f0 ff 49 8b 06 65 ff 00 eb 05 RSP: 0018:ffffc9000147f660 EFLAGS: 00010206 RAX: 0000000000000009 RBX: 0000000000000001 RCX: dffffc0000000000 RDX: ffffc90002d41000 RSI: 000000000000126d RDI: 000000000000126e RBP: ffffc9000147f670 R08: ffffc9000147f70f R09: 1ffff9200028fee1 R10: dffffc0000000000 R11: fffff5200028fee2 R12: 0000000000000000 R13: ffffc9000147f701 R14: 0000000000000049 R15: ffffc9000147f700 FS: 00007fe16355b6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000020c0 CR3: 000000012749e000 CR4: 00000000003506b0 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+0x1e3/0x680 fs/incfs/vfs.c:1473 do_dentry_open+0x7a5/0x10a0 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+0x7a5/0x10a0 fs/open.c:819 vfs_open+0x73/0x80 fs/open.c:944 do_open fs/namei.c:3399 [inline] path_openat+0x26c3/0x3040 fs/namei.c:3517 do_filp_open+0x1df/0x400 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: 0033:0x7fe164b020d9 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:00007fe16355b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fe164d89fa0 RCX: 00007fe164b020d9 RDX: 00000000000001f2 RSI: 0000000000000040 RDI: 00002000000000c0 RBP: 00007fe164b99024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe164d8a038 R14: 00007fe164d89fa0 R15: 00007fffd22205e8 Modules linked in: ---[ end trace 14651fcb8158386e ]--- 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 61 1c b6 ff 48 85 db 74 30 e8 57 1c 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 c4 91 f0 ff 49 8b 06 65 ff 00 eb 05 RSP: 0018:ffffc9000147f660 EFLAGS: 00010206 RAX: 0000000000000009 RBX: 0000000000000001 RCX: dffffc0000000000 RDX: ffffc90002d41000 RSI: 000000000000126d RDI: 000000000000126e RBP: ffffc9000147f670 R08: ffffc9000147f70f R09: 1ffff9200028fee1 R10: dffffc0000000000 R11: fffff5200028fee2 R12: 0000000000000000 R13: ffffc9000147f701 R14: 0000000000000049 R15: ffffc9000147f700 FS: 00007fe16355b6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f11bc420990 CR3: 000000012749e000 CR4: 00000000003506b0 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 61 1c b6 ff call 0xffb61c6c b: 48 85 db test %rbx,%rbx e: 74 30 je 0x40 10: e8 57 1c b6 ff call 0xffb61c6c 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 c4 91 f0 ff call 0xfff091fc 38: 49 8b 06 mov (%r14),%rax 3b: 65 ff 00 incl %gs:(%rax) 3e: eb 05 jmp 0x45