syzbot


WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM

Status: closed as invalid on 2025/11/27 10:19
Subsystems: ext4
[Documentation on labels]
First crash: 27d, last: 26d
Cause bisection: failed (error log, bisect log)
  

Sample crash report:
loop0: detected capacity change from 0 to 512
------------[ cut here ]------------
EA inode 11 i_nlink=2
WARNING: fs/ext4/xattr.c:1058 at 0x0, CPU#0: syz.0.17/6052
Modules linked in:
CPU: 0 UID: 0 PID: 6052 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:ext4_xattr_inode_update_ref+0x4dc/0x570 fs/ext4/xattr.c:1056
Code: 74 08 4c 89 ef e8 14 b0 9a ff 4d 8b 6d 00 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 06 84 c0 75 77 41 8b 17 4c 89 e7 4c 89 ee <67> 48 0f b9 3a 4c 8b 6c 24 28 e9 bd fe ff ff e8 20 af ca 08 44 89
RSP: 0018:ffffc900033a7240 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff1100e65dc99 RCX: dffffc0000000000
RDX: 0000000000000002 RSI: 000000000000000b RDI: ffffffff8f845a00
RBP: ffffc900033a7330 R08: ffff8880732ee4cf R09: 1ffff1100e65dc99
R10: dffffc0000000000 R11: ffffed100e65dc9a R12: ffffffff8f845a00
R13: 000000000000000b R14: 1ffff1100e65dc64 R15: ffff8880732ee320
FS:  0000555556895500(0000) GS:ffff888125e8b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcb154b49c0 CR3: 000000007228e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1081 [inline]
 ext4_xattr_inode_dec_ref_all+0x8c3/0xe00 fs/ext4/xattr.c:1227
 ext4_xattr_delete_inode+0xa4c/0xc10 fs/ext4/xattr.c:2951
 ext4_evict_inode+0xa58/0xe60 fs/ext4/inode.c:270
 evict+0x5f4/0xae0 fs/inode.c:837
 ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:470
 __ext4_fill_super fs/ext4/super.c:5620 [inline]
 ext4_fill_super+0x5946/0x6200 fs/ext4/super.c:5739
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
 vfs_get_tree+0x92/0x2a0 fs/super.c:1751
 fc_mount fs/namespace.c:1209 [inline]
 do_new_mount_fc fs/namespace.c:3646 [inline]
 do_new_mount+0x302/0xa10 fs/namespace.c:3722
 do_mount fs/namespace.c:4045 [inline]
 __do_sys_mount fs/namespace.c:4234 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4211
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc05e190eea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffa51d31d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fffa51d3260 RCX: 00007fc05e190eea
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007fffa51d3220
RBP: 0000200000000180 R08: 00007fffa51d3260 R09: 0000000001800700
R10: 0000000001800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007fffa51d3220 R14: 0000000000000481 R15: 00002000000003c0
 </TASK>
----------------
Code disassembly (best guess):
   0:	74 08                	je     0xa
   2:	4c 89 ef             	mov    %r13,%rdi
   5:	e8 14 b0 9a ff       	call   0xff9ab01e
   a:	4d 8b 6d 00          	mov    0x0(%r13),%r13
   e:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  15:	fc ff df
  18:	41 0f b6 04 06       	movzbl (%r14,%rax,1),%eax
  1d:	84 c0                	test   %al,%al
  1f:	75 77                	jne    0x98
  21:	41 8b 17             	mov    (%r15),%edx
  24:	4c 89 e7             	mov    %r12,%rdi
  27:	4c 89 ee             	mov    %r13,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	4c 8b 6c 24 28       	mov    0x28(%rsp),%r13
  34:	e9 bd fe ff ff       	jmp    0xfffffef6
  39:	e8 20 af ca 08       	call   0x8caaf5e
  3e:	44                   	rex.R
  3f:	89                   	.byte 0x89

Crashes (15):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/26 03:46 linux-next 92fd6e84175b 64219f15 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 22:49 linux-next 92fd6e84175b 64219f15 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 22:02 linux-next 92fd6e84175b 64219f15 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 21:04 linux-next 92fd6e84175b 64219f15 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 20:46 linux-next 92fd6e84175b 64219f15 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 20:28 linux-next 92fd6e84175b 64219f15 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 19:57 linux-next 92fd6e84175b 64219f15 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/26 03:16 linux-next 92fd6e84175b 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/26 03:16 linux-next 92fd6e84175b 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 19:33 linux-next 92fd6e84175b 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 19:27 linux-next 92fd6e84175b 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 19:24 linux-next 92fd6e84175b 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 19:23 linux-next 92fd6e84175b 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 19:15 linux-next 92fd6e84175b 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
2025/11/25 19:15 linux-next 92fd6e84175b 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: fs/ext4/xattr.c:LINE at 0x0, CPU: syz.NUM.NUM/NUM
* Struck through repros no longer work on HEAD.