WARNING in minix_rmdir (2)

Status: upstream: reported C repro on 2026/10/16 07:32
Subsystems: fs
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+8420e667af06b1709c00@syzkaller.appspotmail.com
First crash: 4d06h, last: 4d01h
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
92bf0784 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ WARNING in minix_rmdir (2) 2026/10/13 04:34 2026/10/13 04:34 2026/10/13 04:39 745a967f
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH] minix: reject rmdir of a directory with a corrupted link count 1 (1) 2026/10/16 11:58
[syzbot] [fs?] WARNING in minix_rmdir (2) 0 (1) 2026/10/16 07:32
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in minix_rmdir -1 syz, C done 1 372d 372d 3/3 fixed on 2025/11/17 11:56
linux-6.6 WARNING in minix_rmdir origin:lts-only -1 syz, C error 15 95d 292d 0/2 upstream: reported C repro on 2025/12/27 21:41
linux-5.15 WARNING in minix_rmdir -1 1 691d 691d 0/3 auto-obsoleted due to no activity on 2025/03/04 02:00
linux-5.15 WARNING in minix_rmdir (2) origin:upstream -1 syz, C error 9 49d 446d 0/3 upstream: reported C repro on 2025/07/27 03:10
linux-6.1 WARNING in minix_rmdir (2) origin:lts-only -1 syz, C error 4 275d 275d 0/3 upstream: reported C repro on 2026/01/13 22:36
upstream WARNING in minix_rmdir fs -1 syz, C inconclusive 92 332d 646d 29/29 fixed on 2026/01/07 12:29

Sample crash report:
------------[ cut here ]------------
inode->i_nlink == 0
WARNING: fs/inode.c:408 at drop_nlink+0xc5/0x110 fs/inode.c:408, CPU#0: syz-executor/5454
Modules linked in:
CPU: 0 UID: 0 PID: 5454 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:drop_nlink+0xc5/0x110 fs/inode.c:408
Code: a8 07 00 00 be 08 00 00 00 e8 f7 68 e4 ff f0 48 ff 83 a8 07 00 00 5b 41 5c 41 5e 41 5f 5d e9 52 90 97 09 cc e8 0c e7 71 ff 90 <0f> 0b 90 eb 81 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 5b ff ff ff
RSP: 0018:ffffc900033b7d10 EFLAGS: 00010293
RAX: ffffffff82563a14 RBX: ffff8880439c30b0 RCX: ffff888013d0cb00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff917a977f R09: 1ffffffff22f52ef
R10: dffffc0000000000 R11: fffffbfff22f52f0 R12: 1ffff1100873861f
R13: dffffc0000000000 R14: ffff8880439c30f8 R15: dffffc0000000000
FS:  000055555e111500(0000) GS:ffff88808b0b4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556e57c72048 CR3: 0000000013446000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 inode_dec_link_count include/linux/fs.h:2269 [inline]
 minix_rmdir+0xfc/0x140 fs/minix/namei.c:183
 vfs_rmdir+0x3e6/0x6a0 fs/namei.c:5544
 filename_rmdir+0x292/0x520 fs/namei.c:5601
 __do_sys_unlinkat fs/namei.c:5776 [inline]
 __se_sys_unlinkat+0x71/0x1a0 fs/namei.c:5769
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f819279d2f7
Code: 77 01 c3 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 b8 07 01 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:00007ffef5481018 EFLAGS: 00000207 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f819279d2f7
RDX: 0000000000000200 RSI: 00007ffef54821c0 RDI: 00000000ffffff9c
RBP: 00007f8192834ccb R08: 0000000000018560 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000207 R12: 00007ffef54821c0
R13: 00007f8192834ccb R14: 0000000000028576 R15: 00007ffef5484380
 </TASK>

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/12 12:18 upstream b88c841d1164 4f92358f .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root WARNING in minix_rmdir
2026/10/12 11:18 upstream b88c841d1164 4f92358f .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root WARNING in minix_rmdir
2026/10/12 10:26 upstream b88c841d1164 4f92358f .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root WARNING in minix_rmdir
2026/10/12 09:31 upstream b88c841d1164 4f92358f .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root WARNING in minix_rmdir
2026/10/12 08:47 upstream b88c841d1164 4f92358f .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root WARNING in minix_rmdir
2026/10/12 07:29 upstream b88c841d1164 4f92358f .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in minix_rmdir
* Struck through repros no longer work on HEAD.