syzbot


WARNING in hfsplus_unlink

Status: upstream: reported C repro on 2025/12/30 13:36
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+2f726e7146e76dde94b6@syzkaller.appspotmail.com
First crash: 13d, last: 12d
Bug presence (1)
Date Name Commit Repro Result
2025/12/31 upstream (ToT) c8ebd433459b C [report] WARNING in hfsplus_unlink
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in hfsplus_unlink hfs -1 C inconclusive 36 7d10h 414d 0/29 upstream: reported C repro on 2024/11/24 10:53

Sample crash report:
loop0: detected capacity change from 0 to 1024
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4427 at fs/inode.c:332 drop_nlink+0xbb/0x100 fs/inode.c:332
Modules linked in:
CPU: 1 PID: 4427 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:drop_nlink+0xbb/0x100 fs/inode.c:332
Code: 48 8b 1b 48 8d bb c0 07 00 00 be 08 00 00 00 e8 7b 78 eb ff f0 48 ff 83 c0 07 00 00 5b 41 5c 41 5e 41 5f 5d c3 e8 75 45 9b ff <0f> 0b eb 88 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 62 ff ff ff 4c
RSP: 0018:ffffc900033c7c10 EFLAGS: 00010293
RAX: ffffffff81e59a5b RBX: ffff88802e56aa30 RCX: ffff88802b3b0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffff52000678eed
R10: fffff52000678eed R11: 1ffff92000678eec R12: 1ffff11005cad54f
R13: ffff888069b33080 R14: ffff88802e56aa78 R15: dffffc0000000000
FS:  0000555572a2b500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f98417909c0 CR3: 0000000026a56000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 hfsplus_unlink+0x3c8/0x760 fs/hfsplus/dir.c:381
 vfs_unlink+0x385/0x600 fs/namei.c:4330
 do_unlinkat+0x324/0x560 fs/namei.c:4398
 __do_sys_unlinkat fs/namei.c:4441 [inline]
 __se_sys_unlinkat fs/namei.c:4434 [inline]
 __x64_sys_unlinkat+0xd1/0xe0 fs/namei.c:4434
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2f2738f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff00e83408 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007f2f275e5fa0 RCX: 00007f2f2738f749
RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f2f27413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f275e5fa0 R14: 00007f2f275e5fa0 R15: 0000000000000003
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/30 17:37 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan WARNING in hfsplus_unlink
2025/12/30 16:38 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan WARNING in hfsplus_unlink
2025/12/30 15:36 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan WARNING in hfsplus_unlink
2025/12/30 14:35 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan WARNING in hfsplus_unlink
2025/12/30 13:35 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in hfsplus_unlink
* Struck through repros no longer work on HEAD.