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WARNING in ext4_xattr_inode_update_ref

Status: upstream: reported C repro on 2025/09/07 01:50
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+23ef1ff7166a7f106a9d@syzkaller.appspotmail.com
First crash: 169d, last: 8h02m
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2025/10/27 upstream (ToT) dcb6fa37fd7b C [report] WARNING in ext4_xattr_inode_update_ref
▶ ▼ 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 1130 6h27m 165d 0/2 upstream: reported C repro on 2025/09/10 09:46
upstream WARNING in ext4_xattr_inode_update_ref ext4 -1 C error 1291 116d 165d 29/29 fixed on 2025/10/29 21:02
linux-5.15 WARNING in ext4_xattr_inode_update_ref origin:upstream -1 C 1776 9h54m 165d 0/3 upstream: reported C repro on 2025/09/10 09:56
upstream WARNING in ext4_xattr_inode_update_ref (2) ext4 -1 C error 4790 8m 115d 0/29 upstream: reported C repro on 2025/10/30 22:34

Sample crash report:
EXT4-fs: Warning: mounting with an experimental mount option 'dioread_nolock' for blocksize < PAGE_SIZE
EXT4-fs error (device loop0): ext4_orphan_get:1425: comm syz.0.47: bad orphan inode 15
ext4_test_bit(bit=14, block=4) = 1
is_bad_inode(inode)=0
NEXT_ORPHAN(inode)=1771765368
max_ino=32
i_nlink=0
------------[ cut here ]------------
EA inode 11 i_nlink=0
WARNING: CPU: 1 PID: 4494 at fs/ext4/xattr.c:1006 ext4_xattr_inode_update_ref+0x4e7/0x540 fs/ext4/xattr.c:1004
Modules linked in:
CPU: 1 PID: 4494 Comm: syz.0.47 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:ext4_xattr_inode_update_ref+0x4e7/0x540 fs/ext4/xattr.c:1004
Code: 7c 24 40 4c 89 f8 48 c1 e8 03 42 80 3c 30 00 74 08 4c 89 ff e8 2a c6 9b ff 49 8b 37 48 c7 c7 c0 a0 a0 8a 89 da e8 e9 48 16 ff <0f> 0b 4c 8b 64 24 08 4c 8b 7c 24 10 e9 a9 fe ff ff e8 83 0a f5 07
RSP: 0018:ffffc90003547280 EFLAGS: 00010246
RAX: 6368d78bcc8f9700 RBX: 0000000000000000 RCX: ffff88807d5f1dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc90003547370 R08: ffffc90003546f07 R09: 1ffff920006a8de0
R10: dffffc0000000000 R11: fffff520006a8de1 R12: ffff8880689ac8e8
R13: 1ffff1100d13595c R14: dffffc0000000000 R15: ffff8880689ac928
FS:  0000555586bd8500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f625a6ac000 CR3: 000000005b9fa000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1029 [inline]
 ext4_xattr_inode_dec_ref_all+0xb03/0x1060 fs/ext4/xattr.c:1175
 ext4_xattr_delete_inode+0xad1/0xca0 fs/ext4/xattr.c:2896
 ext4_evict_inode+0xc45/0x1110 fs/ext4/inode.c:296
 evict+0x4c9/0x8d0 fs/inode.c:705
 ext4_orphan_get+0x4e3/0x5f0 fs/ext4/ialloc.c:1440
 ext4_orphan_cleanup+0xa9d/0x1420 fs/ext4/orphan.c:465
 __ext4_fill_super fs/ext4/super.c:5556 [inline]
 ext4_fill_super+0x7829/0x7dc0 fs/ext4/super.c:5687
 get_tree_bdev+0x3f1/0x610 fs/super.c:1366
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x24a/0xa40 fs/namespace.c:3078
 do_mount fs/namespace.c:3421 [inline]
 __do_sys_mount fs/namespace.c:3629 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe29319d8ca
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffd9dda5c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fffd9dda650 RCX: 00007fe29319d8ca
RDX: 0000200000000180 RSI: 0000200000000000 RDI: 00007fffd9dda610
RBP: 0000200000000180 R08: 00007fffd9dda650 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 0000200000000000
R13: 00007fffd9dda610 R14: 000000000000047a R15: 00002000000000c0
 </TASK>

Crashes (3160):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/22 13:02 linux-6.1.y 779f9571ac3e 6e7b5511 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/04 11:57 linux-6.1.y cd9b81672742 42b01fab .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/01/16 17:38 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/01/15 12:59 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/01/14 11:22 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/01/12 21:25 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2025/10/25 17:50 linux-6.1.y 8e6e2188d949 c0460fcd .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/18 23:19 linux-6.1.y 8ce36b2849ef 77d4d919 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/17 12:14 linux-6.1.y 8ce36b2849ef e439b951 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/16 22:20 linux-6.1.y 8ce36b2849ef 5d52cba5 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/15 01:29 linux-6.1.y 8ce36b2849ef 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/09 18:15 linux-6.1.y 0182cb5b74ee df949cd9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/05 17:17 linux-6.1.y cd9b81672742 4936e85c .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/01/23 20:20 linux-6.1.y cd9b81672742 e2b1b6e6 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/01/22 16:25 linux-6.1.y cd9b81672742 a16aed1d .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/01/20 23:06 linux-6.1.y cd9b81672742 06648d9c .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/01/19 08:11 linux-6.1.y cd9b81672742 20d37d28 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/01/15 13:11 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/07 14:08 linux-6.1.y 0182cb5b74ee f20fc9f9 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/22 19:03 linux-6.1.y 779f9571ac3e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/22 04:36 linux-6.1.y 779f9571ac3e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/21 05:39 linux-6.1.y 779f9571ac3e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/20 16:56 linux-6.1.y 779f9571ac3e 17d780d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/20 05:39 linux-6.1.y 779f9571ac3e c8d8c52d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/20 02:49 linux-6.1.y 779f9571ac3e c8d8c52d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/19 12:17 linux-6.1.y 8ce36b2849ef 746545b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/17 23:00 linux-6.1.y 8ce36b2849ef 06ec4f7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/17 11:11 linux-6.1.y 8ce36b2849ef e439b951 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/15 03:06 linux-6.1.y 8ce36b2849ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/15 00:44 linux-6.1.y 8ce36b2849ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/10 20:33 linux-6.1.y 0182cb5b74ee 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/09 01:24 linux-6.1.y 0182cb5b74ee 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/08 20:10 linux-6.1.y 0182cb5b74ee 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/07 07:09 linux-6.1.y 0182cb5b74ee f20fc9f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/05 05:53 linux-6.1.y cd9b81672742 ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/05 01:12 linux-6.1.y cd9b81672742 ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/04 21:08 linux-6.1.y cd9b81672742 ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/03 17:20 linux-6.1.y cd9b81672742 6df4c87a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/03 05:01 linux-6.1.y cd9b81672742 d78927dd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/02 17:36 linux-6.1.y cd9b81672742 018ebef2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_xattr_inode_update_ref
2026/02/22 16:51 linux-6.1.y 779f9571ac3e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/22 11:04 linux-6.1.y 779f9571ac3e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/22 02:45 linux-6.1.y 779f9571ac3e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/22 01:48 linux-6.1.y 779f9571ac3e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/20 23:51 linux-6.1.y 779f9571ac3e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/20 11:43 linux-6.1.y 779f9571ac3e 17d780d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/19 23:13 linux-6.1.y 779f9571ac3e c8d8c52d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/19 08:56 linux-6.1.y 8ce36b2849ef 746545b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/18 10:04 linux-6.1.y 8ce36b2849ef 39751c21 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/17 21:26 linux-6.1.y 8ce36b2849ef 06ec4f7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/17 09:19 linux-6.1.y 8ce36b2849ef e439b951 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/16 00:15 linux-6.1.y 8ce36b2849ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/15 10:45 linux-6.1.y 8ce36b2849ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/15 10:43 linux-6.1.y 8ce36b2849ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/13 22:25 linux-6.1.y 8ce36b2849ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/10 17:37 linux-6.1.y 0182cb5b74ee 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/08 22:18 linux-6.1.y 0182cb5b74ee 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/08 22:18 linux-6.1.y 0182cb5b74ee 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/06 16:58 linux-6.1.y cd9b81672742 97745f52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/05 14:43 linux-6.1.y cd9b81672742 4936e85c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/05 04:25 linux-6.1.y cd9b81672742 ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/04 03:02 linux-6.1.y cd9b81672742 42b01fab .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/04 03:01 linux-6.1.y cd9b81672742 42b01fab .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/03 14:39 linux-6.1.y cd9b81672742 6df4c87a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/03 02:39 linux-6.1.y cd9b81672742 d78927dd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2026/02/02 16:34 linux-6.1.y cd9b81672742 018ebef2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2025/09/07 02:01 linux-6.1.y 28c695c365e1 d291dd2d .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
2025/09/07 01:49 linux-6.1.y 28c695c365e1 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in ext4_xattr_inode_update_ref
* Struck through repros no longer work on HEAD.