syzbot


WARNING in ext4_xattr_inode_update_ref (2)

Status: upstream: reported C repro on 2025/10/30 22:34
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+76916a45d2294b551fd9@syzkaller.appspotmail.com
First crash: 42d, last: 48m
Cause bisection: failed (error log, bisect log)
  
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly ext4 report (Nov 2025) 0 (1) 2025/11/28 21:21
[syzbot] [ext4?] WARNING in ext4_xattr_inode_update_ref (2) 2 (7) 2025/11/06 07:26
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 WARNING in ext4_xattr_inode_update_ref origin:upstream -1 C 647 55m 91d 0/2 upstream: reported C repro on 2025/09/10 09:46
linux-6.1 WARNING in ext4_xattr_inode_update_ref origin:upstream -1 C 1790 5h46m 95d 0/3 upstream: reported C repro on 2025/09/07 01:50
upstream WARNING in ext4_xattr_inode_update_ref ext4 -1 C error 1291 42d 91d 29/29 fixed on 2025/10/29 21:02
linux-5.15 WARNING in ext4_xattr_inode_update_ref origin:upstream -1 C 1007 4h16m 91d 0/3 upstream: reported C repro on 2025/09/10 09:56
Last patch testing requests (4)
Created Duration User Patch Repo Result
2025/11/06 07:26 16m lizhi.xu@windriver.com patch upstream report log
2025/11/03 08:23 14m lizhi.xu@windriver.com patch upstream report log
2025/11/03 07:46 14m lizhi.xu@windriver.com patch upstream report log
2025/10/31 01:53 21m lizhi.xu@windriver.com patch upstream OK 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#1: syz.0.17/6068
Modules linked in:
CPU: 1 UID: 0 PID: 6068 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(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 c4 a3 9f 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 30 bb 4f 08 44 89
RSP: 0018:ffffc90003be7100 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff11008573c93 RCX: dffffc0000000000
RDX: 0000000000000002 RSI: 000000000000000b RDI: ffffffff8ee11b10
RBP: ffffc90003be71f8 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1008573c94 R12: ffffffff8ee11b10
R13: 000000000000000b R14: 1ffff11008573c58 R15: ffff888042b9e2c0
FS:  000055556f186500(0000) GS:ffff888126e06000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f097cde49c0 CR3: 000000001f786000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1081 [inline]
 ext4_xattr_set_entry+0xabb/0x1e20 fs/ext4/xattr.c:1723
 ext4_xattr_ibody_set+0x254/0x6a0 fs/ext4/xattr.c:2272
 ext4_xattr_move_to_block fs/ext4/xattr.c:2675 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2743 [inline]
 ext4_expand_extra_isize_ea+0x13ad/0x1ea0 fs/ext4/xattr.c:2831
 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6349
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6392 [inline]
 __ext4_mark_inode_dirty+0x45c/0x6e0 fs/ext4/inode.c:6470
 ext4_evict_inode+0x79c/0xe60 fs/ext4/inode.c:253
 evict+0x5f4/0xae0 fs/inode.c:837
 ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:472
 __ext4_fill_super fs/ext4/super.c:5658 [inline]
 ext4_fill_super+0x58ad/0x6170 fs/ext4/super.c:5777
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
 vfs_get_tree+0x92/0x2a0 fs/super.c:1751
 fc_mount fs/namespace.c:1199 [inline]
 do_new_mount_fc fs/namespace.c:3636 [inline]
 do_new_mount+0x302/0xa10 fs/namespace.c:3712
 do_mount fs/namespace.c:4035 [inline]
 __do_sys_mount fs/namespace.c:4224 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4201
 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: 0033:0x7febc07f0eea
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:00007ffef9534368 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffef95343f0 RCX: 00007febc07f0eea
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007ffef95343b0
RBP: 0000200000000180 R08: 00007ffef95343f0 R09: 0000000000800718
R10: 0000000000800718 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007ffef95343b0 R14: 000000000000046f R15: 0000200000000200
 </TASK>
----------------
Code disassembly (best guess):
   0:	74 08                	je     0xa
   2:	4c 89 ef             	mov    %r13,%rdi
   5:	e8 c4 a3 9f ff       	call   0xff9fa3ce
   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 30 bb 4f 08       	call   0x84fbb6e
  3e:	44                   	rex.R
  3f:	89                   	.byte 0x89

Crashes (1771):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/11 03:21 upstream 0048fbb4011e d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs WARNING in ext4_xattr_inode_update_ref
2025/12/10 02:09 upstream cb015814f8b6 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs WARNING in ext4_xattr_inode_update_ref
2025/12/09 16:29 upstream cfd4039213e7 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs WARNING in ext4_xattr_inode_update_ref
2025/12/08 10:33 upstream ba65a4e7120a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs WARNING in ext4_xattr_inode_update_ref
2025/12/07 17:14 upstream 37bb2e7217b0 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs WARNING in ext4_xattr_inode_update_ref
2025/12/06 12:53 upstream 416f99c3b16f d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs WARNING in ext4_xattr_inode_update_ref
2025/11/26 01:21 upstream 8a2bcda5e139 64219f15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs WARNING in ext4_xattr_inode_update_ref
2025/10/31 10:24 upstream d127176862a9 2c50b6a9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs WARNING in ext4_xattr_inode_update_ref
2025/10/30 19:51 upstream e53642b87a4f 2c50b6a9 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/11 01:45 upstream 0048fbb4011e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_xattr_inode_update_ref
2025/12/10 14:28 upstream c9b47175e913 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_xattr_inode_update_ref
2025/12/10 14:27 upstream c9b47175e913 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_xattr_inode_update_ref
2025/12/10 12:42 upstream c9b47175e913 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/10 06:54 upstream c9b47175e913 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/09 22:50 upstream cb015814f8b6 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_xattr_inode_update_ref
2025/12/09 11:29 upstream a110f942672c d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_xattr_inode_update_ref
2025/12/09 09:02 upstream a110f942672c d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_xattr_inode_update_ref
2025/12/09 07:41 upstream a110f942672c d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/09 06:44 upstream cfd4039213e7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in ext4_xattr_inode_update_ref
2025/12/09 02:54 upstream a110f942672c d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/08 08:44 upstream c2f2b01b74be d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 22:58 upstream 37bb2e7217b0 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 20:35 upstream 37bb2e7217b0 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 19:16 upstream 37bb2e7217b0 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 05:56 upstream 50471f8b7371 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 05:23 upstream 50471f8b7371 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/06 20:31 upstream 416f99c3b16f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_xattr_inode_update_ref
2025/12/06 17:44 upstream 416f99c3b16f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_xattr_inode_update_ref
2025/12/11 03:41 upstream 0048fbb4011e d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/10 23:01 upstream 0048fbb4011e d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/10 17:49 upstream 0048fbb4011e d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/10 09:49 upstream c9b47175e913 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/10 05:57 upstream c9b47175e913 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/10 00:26 upstream cb015814f8b6 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/09 20:41 upstream cb015814f8b6 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/09 15:27 upstream cb015814f8b6 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/09 04:29 upstream a110f942672c d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/09 00:58 upstream a110f942672c d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/08 17:38 upstream c2f2b01b74be d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/08 17:36 upstream c2f2b01b74be d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/08 05:47 upstream c2f2b01b74be d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 21:37 upstream 37bb2e7217b0 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 16:21 upstream 37bb2e7217b0 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 10:14 upstream c06c303832ec d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 07:16 upstream c06c303832ec d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ext4_xattr_inode_update_ref
2025/12/10 10:22 linux-next 008d3547aae5 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/10 08:29 linux-next 008d3547aae5 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/08 07:30 linux-next 82bcd04d124a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/08 07:26 linux-next 82bcd04d124a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 14:57 linux-next 6987d58a9cbc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 12:35 linux-next 6987d58a9cbc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 02:14 linux-next 6987d58a9cbc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/07 02:04 linux-next 6987d58a9cbc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/10/29 21:13 linux-next f9ba12abc528 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ext4_xattr_inode_update_ref
2025/12/09 04:30 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 05c93f3395ed d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in ext4_xattr_inode_update_ref
2025/12/07 18:09 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 05c93f3395ed d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in ext4_xattr_inode_update_ref
* Struck through repros no longer work on HEAD.