general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] CPU: 1 PID: 296 Comm: syz-executor222 Not tainted 6.1.25-syzkaller-00088-gcd94fe67fd33 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 RIP: 0010:traverse_mounts fs/namei.c:1428 [inline] RIP: 0010:handle_mounts fs/namei.c:1540 [inline] RIP: 0010:step_into+0x1c4/0x1090 fs/namei.c:1831 Code: c0 0f 85 bb 0b 00 00 44 8b 3b 43 80 3c 34 00 74 0a 48 8b 7c 24 10 e8 9b fe f2 ff 48 8b 9c 24 d8 00 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 a8 0b 00 00 8b 1b 89 de 81 e6 00 00 07 RSP: 0018:ffffc90000d57a20 EFLAGS: 00010207 RAX: 0000000000000003 RBX: 000000000000001e RCX: ffff888109463cc0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000d57b70 R08: ffffffff81c82c79 R09: ffffed1021ddf89d R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920001aaf5f R13: ffffc90000d57ca0 R14: dffffc0000000000 R15: 0000000000000081 FS: 00007f140f58b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020005000 CR3: 0000000121954000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: walk_component+0x234/0x410 fs/namei.c:1999 lookup_last fs/namei.c:2450 [inline] path_lookupat+0x16d/0x450 fs/namei.c:2474 filename_lookup+0x251/0x600 fs/namei.c:2503 user_path_at_empty+0x43/0x1a0 fs/namei.c:2876 user_path_at include/linux/namei.h:57 [inline] ksys_umount fs/namespace.c:1822 [inline] __do_sys_umount fs/namespace.c:1830 [inline] __se_sys_umount fs/namespace.c:1828 [inline] __x64_sys_umount+0xf0/0x170 fs/namespace.c:1828 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f140f5c9479 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f140f58b218 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007f140f6563e8 RCX: 00007f140f5c9479 RDX: 00007f140f5c9479 RSI: 0000000000000004 RDI: 0000000020000080 RBP: 00007f140f6563e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f140f62301c R13: 00007f140f623038 R14: 00007f140f62100e R15: 0030656c69662f30 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:traverse_mounts fs/namei.c:1428 [inline] RIP: 0010:handle_mounts fs/namei.c:1540 [inline] RIP: 0010:step_into+0x1c4/0x1090 fs/namei.c:1831 Code: c0 0f 85 bb 0b 00 00 44 8b 3b 43 80 3c 34 00 74 0a 48 8b 7c 24 10 e8 9b fe f2 ff 48 8b 9c 24 d8 00 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 a8 0b 00 00 8b 1b 89 de 81 e6 00 00 07 RSP: 0018:ffffc90000d57a20 EFLAGS: 00010207 RAX: 0000000000000003 RBX: 000000000000001e RCX: ffff888109463cc0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000d57b70 R08: ffffffff81c82c79 R09: ffffed1021ddf89d R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920001aaf5f R13: ffffc90000d57ca0 R14: dffffc0000000000 R15: 0000000000000081 FS: 00007f140f58b6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f140f5cada0 CR3: 0000000121954000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: c0 0f 85 rorb $0x85,(%rdi) 3: bb 0b 00 00 44 mov $0x4400000b,%ebx 8: 8b 3b mov (%rbx),%edi a: 43 80 3c 34 00 cmpb $0x0,(%r12,%r14,1) f: 74 0a je 0x1b 11: 48 8b 7c 24 10 mov 0x10(%rsp),%rdi 16: e8 9b fe f2 ff call 0xfff2feb6 1b: 48 8b 9c 24 d8 00 00 mov 0xd8(%rsp),%rbx 22: 00 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 0f 85 a8 0b 00 00 jne 0xbdf 37: 8b 1b mov (%rbx),%ebx 39: 89 de mov %ebx,%esi 3b: 81 .byte 0x81 3c: e6 00 out %al,$0x0 3e: 00 07 add %al,(%rdi)