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: 289 Comm: syz-executor198 Not tainted 5.10.194-syzkaller-00508-ga27512601c2d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 RIP: 0010:traverse_mounts fs/namei.c:1357 [inline] RIP: 0010:handle_mounts fs/namei.c:1477 [inline] RIP: 0010:step_into+0x1b9/0xec0 fs/namei.c:1782 Code: 24 0f 85 cf 0a 00 00 44 8b 3a 43 80 3c 2c 00 74 0a 48 8b 7c 24 18 e8 46 9d f3 ff 48 8b 9c 24 b8 00 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 c1 0a 00 00 8b 1b 89 de 81 e6 00 00 07 RSP: 0018:ffffc90000b179c0 EFLAGS: 00010207 RAX: 0000000000000003 RBX: 000000000000001e RCX: ffff88811eaf4f00 RDX: ffffc90000b17d18 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000b17af0 R08: ffffffff81b4571f R09: ffffed1023815a55 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000162f4f R13: dffffc0000000000 R14: ffffc90000b17ce0 R15: 0000000000000089 FS: 00007f310e4726c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020005000 CR3: 000000011eb13000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: walk_component+0x359/0x610 fs/namei.c:1958 lookup_last fs/namei.c:2403 [inline] path_lookupat+0x16d/0x450 fs/namei.c:2427 filename_lookup+0x26a/0x6f0 fs/namei.c:2460 user_path_at_empty+0x40/0x50 fs/namei.c:2740 user_path_at include/linux/namei.h:60 [inline] ksys_umount fs/namespace.c:1761 [inline] __do_sys_umount fs/namespace.c:1769 [inline] __se_sys_umount fs/namespace.c:1767 [inline] __x64_sys_umount+0xf0/0x170 fs/namespace.c:1767 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xc6 RIP: 0033:0x7f310e4b0479 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:00007f310e472218 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007f310e53d3e8 RCX: 00007f310e4b0479 RDX: 00007f310e4b0479 RSI: 0000000000000004 RDI: 0000000020000080 RBP: 00007f310e53d3e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f310e50a01c R13: 00007f310e50a038 R14: 00007f310e50800e R15: 0030656c69662f30 Modules linked in: ---[ end trace d4288ea42d476f6d ]--- RIP: 0010:traverse_mounts fs/namei.c:1357 [inline] RIP: 0010:handle_mounts fs/namei.c:1477 [inline] RIP: 0010:step_into+0x1b9/0xec0 fs/namei.c:1782 Code: 24 0f 85 cf 0a 00 00 44 8b 3a 43 80 3c 2c 00 74 0a 48 8b 7c 24 18 e8 46 9d f3 ff 48 8b 9c 24 b8 00 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 c1 0a 00 00 8b 1b 89 de 81 e6 00 00 07 RSP: 0018:ffffc90000b179c0 EFLAGS: 00010207 RAX: 0000000000000003 RBX: 000000000000001e RCX: ffff88811eaf4f00 RDX: ffffc90000b17d18 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000b17af0 R08: ffffffff81b4571f R09: ffffed1023815a55 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000162f4f R13: dffffc0000000000 R14: ffffc90000b17ce0 R15: 0000000000000089 FS: 00007f310e4726c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020005000 CR3: 000000011eb13000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 24 0f and $0xf,%al 2: 85 cf test %ecx,%edi 4: 0a 00 or (%rax),%al 6: 00 44 8b 3a add %al,0x3a(%rbx,%rcx,4) a: 43 80 3c 2c 00 cmpb $0x0,(%r12,%r13,1) f: 74 0a je 0x1b 11: 48 8b 7c 24 18 mov 0x18(%rsp),%rdi 16: e8 46 9d f3 ff call 0xfff39d61 1b: 48 8b 9c 24 b8 00 00 mov 0xb8(%rsp),%rbx 22: 00 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 0f 85 c1 0a 00 00 jne 0xaf8 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)