syzbot


linux-6.6.y test error: general protection fault in fgetxattr

Status: upstream: reported on 2026/04/02 22:24
Reported-by: syzbot+09d67970d561cc40ed26@syzkaller.appspotmail.com
First crash: 25d, last: 25d

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000030: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000180-0x0000000000000187]
CPU: 1 PID: 5906 Comm: syz.2.129 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:file_mnt_idmap include/linux/fs.h:2481 [inline]
RIP: 0010:__do_sys_fgetxattr fs/xattr.c:814 [inline]
RIP: 0010:__se_sys_fgetxattr+0x132/0x370 fs/xattr.c:808
Code: 89 fe e8 d1 33 8e ff 45 85 ff 0f 84 23 02 00 00 e8 13 30 8e ff eb 05 e8 0c 30 8e ff 4c 8d bb 80 01 00 00 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 cf 66 e6 ff 4d 8b 27 49 83 c4 18
RSP: 0018:ffffc9000498fd00 EFLAGS: 00010206
RAX: 0000000000000030 RBX: 0000000000000000 RCX: ffff88803136bc00
RDX: 0000000000000000 RSI: 0000000000000100 RDI: 00000000ffffffff
RBP: ffffc9000498ff10 R08: ffff88807b1a61c3 R09: 1ffff1100f634c38
R10: dffffc0000000000 R11: ffffed100f634c39 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff92000931fac R15: 0000000000000180
FS:  0000555564d1e500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa4d6f2ba40 CR3: 000000002f847000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa4d6f9c819
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:00007fff29ca4158 EFLAGS: 00000246 ORIG_RAX: 00000000000000c1
RAX: ffffffffffffffda RBX: 00007fa4d7215fa0 RCX: 00007fa4d6f9c819
RDX: 0000200000000000 RSI: 0000200000000000 RDI: ffffffffffffffff
RBP: 00007fa4d7032c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa4d7215fac R14: 00007fa4d7215fa0 R15: 00007fa4d7215fa0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:file_mnt_idmap include/linux/fs.h:2481 [inline]
RIP: 0010:__do_sys_fgetxattr fs/xattr.c:814 [inline]
RIP: 0010:__se_sys_fgetxattr+0x132/0x370 fs/xattr.c:808
Code: 89 fe e8 d1 33 8e ff 45 85 ff 0f 84 23 02 00 00 e8 13 30 8e ff eb 05 e8 0c 30 8e ff 4c 8d bb 80 01 00 00 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 cf 66 e6 ff 4d 8b 27 49 83 c4 18
RSP: 0018:ffffc9000498fd00 EFLAGS: 00010206
RAX: 0000000000000030 RBX: 0000000000000000 RCX: ffff88803136bc00
RDX: 0000000000000000 RSI: 0000000000000100 RDI: 00000000ffffffff
RBP: ffffc9000498ff10 R08: ffff88807b1a61c3 R09: 1ffff1100f634c38
R10: dffffc0000000000 R11: ffffed100f634c39 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff92000931fac R15: 0000000000000180
FS:  0000555564d1e500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c914a71e28 CR3: 000000002f847000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
   0:	89 fe                	mov    %edi,%esi
   2:	e8 d1 33 8e ff       	call   0xff8e33d8
   7:	45 85 ff             	test   %r15d,%r15d
   a:	0f 84 23 02 00 00    	je     0x233
  10:	e8 13 30 8e ff       	call   0xff8e3028
  15:	eb 05                	jmp    0x1c
  17:	e8 0c 30 8e ff       	call   0xff8e3028
  1c:	4c 8d bb 80 01 00 00 	lea    0x180(%rbx),%r15
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 ff             	mov    %r15,%rdi
  34:	e8 cf 66 e6 ff       	call   0xffe66708
  39:	4d 8b 27             	mov    (%r15),%r12
  3c:	49 83 c4 18          	add    $0x18,%r12

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/02 22:23 linux-6.6.y 08667c1437c0 4440e7c2 .config console log report [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan linux-6.6.y test error: general protection fault in fgetxattr
* Struck through repros no longer work on HEAD.