syzbot


WARNING in ext4_xattr_inode_update_ref

Status: upstream: reported C repro on 2025/09/10 09:56
Reported-by: syzbot+b56a869e22ff21696a84@syzkaller.appspotmail.com
First crash: 1d06h, last: 13h12m
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 WARNING in ext4_xattr_inode_update_ref -1 C 9 15h16m 1d06h 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 27 12h22m 4d14h 0/3 upstream: reported C repro on 2025/09/07 01:50
upstream WARNING in ext4_xattr_inode_update_ref ext4 -1 C error 55 11h32m 15h59m 0/29 upstream: reported C repro on 2025/09/11 00:08

Sample crash report:
EXT4-fs warning (device loop0): ext4_xattr_inode_get:509: inode #11: comm syz.0.17: EA inode hash validation failed
EXT4-fs warning (device loop0): ext4_expand_extra_isize_ea:2825: Unable to expand inode 15. Delete some EAs or run e2fsck.
------------[ cut here ]------------
EA inode 11 ref_count=-1
WARNING: CPU: 1 PID: 4322 at fs/ext4/xattr.c:1016 ext4_xattr_inode_update_ref+0x47b/0x570 fs/ext4/xattr.c:1015
Modules linked in:
CPU: 1 PID: 4322 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:ext4_xattr_inode_update_ref+0x47b/0x570 fs/ext4/xattr.c:1015
Code: 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 f7 e8 17 e7 a2 ff 49 8b 36 48 c7 c7 a0 6f 1d 8a 4c 89 e2 e8 05 dc 84 07 <0f> 0b 48 8b 5c 24 10 4c 8b 7c 24 18 4c 8d 6c 24 60 e9 af fe ff ff
RSP: 0018:ffffc90002fdf3a0 EFLAGS: 00010246
RAX: a96745ec3e4e1900 RBX: 00000000ffffffff RCX: ffff88802146d940
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc90002fdf490 R08: dffffc0000000000 R09: ffffed1017224f24
R10: ffffed1017224f24 R11: 1ffff11017224f23 R12: ffffffffffffffff
R13: ffffc90002fdf400 R14: ffff88806710f088 R15: 0000000000000001
FS:  0000555585ad3500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556caa79e000 CR3: 000000007a6db000 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:1044 [inline]
 ext4_xattr_inode_dec_ref_all+0x982/0xf30 fs/ext4/xattr.c:1186
 ext4_xattr_delete_inode+0x9f1/0xbb0 fs/ext4/xattr.c:2921
 ext4_evict_inode+0xc47/0x1080 fs/ext4/inode.c:299
 evict+0x485/0x870 fs/inode.c:647
 ext4_orphan_cleanup+0xaa9/0x12e0 fs/ext4/orphan.c:474
 ext4_fill_super+0x92f0/0x9a60 fs/ext4/super.c:4975
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3025
 do_mount fs/namespace.c:3368 [inline]
 __do_sys_mount fs/namespace.c:3576 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3553
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0f559d834a
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:00007ffff99fb0a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffff99fb130 RCX: 00007f0f559d834a
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007ffff99fb0f0
RBP: 0000200000000180 R08: 00007ffff99fb130 R09: 000000000080078b
R10: 000000000080078b R11: 0000000000000246 R12: 00002000000001c0
R13: 00007ffff99fb0f0 R14: 0000000000000473 R15: 0000200000000680
 </TASK>

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/10 21:01 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/11 02:55 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/11 02:53 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/11 02:13 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/11 02:12 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/10 16:31 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/10 16:31 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/10 15:22 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/10 15:22 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/10 09:58 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/10 09:58 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/10 09:57 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
2025/09/10 09:55 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in ext4_xattr_inode_update_ref
* Struck through repros no longer work on HEAD.