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VFS: Busy inodes after unmount (use-after-free)

Status: upstream: reported C repro on 2023/03/18 09:53
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+8f448a401cc209730b34@syzkaller.appspotmail.com
First crash: 1200d, last: 6h15m
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2023/09/15 linux-6.1.y (ToT) 09045dae0d90 C [report] VFS: Busy inodes after unmount (use-after-free)
2023/09/15 upstream (ToT) 9fdfb15a3dbf C Didn't crash
▶ ▼ Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-54 VFS: Busy inodes after unmount (use-after-free) 2 C 4 1165d 1221d 0/2 auto-obsoleted due to no activity on 2023/08/20 15:35
upstream VFS: Busy inodes after unmount (use-after-free) (2) btrfs 2 C error 277 303d 415d 29/29 fixed on 2025/09/04 16:57
android-5-15 VFS: Busy inodes after unmount (use-after-free) origin:downstream 2 C error done 2 1119d 1220d 0/2 auto-obsoleted due to no activity on 2023/09/15 20:27
android-5-10 VFS: Busy inodes after unmount (use-after-free) 2 C done inconclusive 1 1220d 1220d 0/2 auto-obsoleted due to no activity on 2023/06/25 23:02
linux-6.6 VFS: Busy inodes after unmount (use-after-free) origin:upstream missing-backport 2 C inconclusive 829 5h47m 335d 0/2 upstream: reported C repro on 2025/07/29 23:52
upstream VFS: Busy inodes after unmount (use-after-free) (3) fs 2 C error 85 243d 273d 29/29 fixed on 2025/11/18 08:45
upstream VFS: Busy inodes after unmount (use-after-free) (4) prio:high jfs 2 C error 38 1d04h 187d 0/29 upstream: reported C repro on 2025/12/25 14:06
upstream VFS: Busy inodes after unmount (use-after-free) fs 2 C error 55684 421d 1252d 28/29 fixed on 2025/05/06 15:33
linux-5.15 VFS: Busy inodes after unmount (use-after-free) missing-backport origin:lts-only 2 C done 3204 6h13m 1199d 0/3 upstream: reported C repro on 2023/03/19 11:46
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2023/10/08 00:57 7h55m fix candidate upstream OK (3) job log

Sample crash report:
ocfs2: Unmounting device (7,0) on (node local)
VFS: Busy inodes after unmount of loop0 (ocfs2)
------------[ cut here ]------------
kernel BUG at fs/super.c:505!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4246 Comm: syz-executor178 Not tainted 6.1.119-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:generic_shutdown_super+0x339/0x340 fs/super.c:503
Code: 8b 1b 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 29 90 f0 ff 48 8b 13 48 c7 c7 60 60 19 8b 4c 89 fe e8 d7 36 be 08 <0f> 0b 0f 1f 44 00 00 41 57 41 56 53 49 89 fe 49 bf 00 00 00 00 00
RSP: 0018:ffffc90003be7cf8 EFLAGS: 00010246
RAX: 000000000000002f RBX: ffffffff8d8101c0 RCX: d5a708bd91106a00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 1ffff1100f3dfcfb R08: ffffffff816e6d5c R09: fffff5200077cf41
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff8b4c57d8 R15: ffff888079efe6a8
FS:  0000555567d1a380(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f348b777130 CR3: 000000007b82d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kill_block_super+0x7a/0xe0 fs/super.c:1470
 deactivate_locked_super+0xa0/0x110 fs/super.c:332
 cleanup_mnt+0x490/0x520 fs/namespace.c:1186
 task_work_run+0x246/0x300 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f348b6fc447
Code: 07 00 48 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffea1450ea8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f348b6fc447
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffea1450f60
RBP: 00007ffea1450f60 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007ffea1451fc0
R13: 0000555567d1b6c0 R14: 0000000000000001 R15: 431bde82d7b634db
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:generic_shutdown_super+0x339/0x340 fs/super.c:503
Code: 8b 1b 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 29 90 f0 ff 48 8b 13 48 c7 c7 60 60 19 8b 4c 89 fe e8 d7 36 be 08 <0f> 0b 0f 1f 44 00 00 41 57 41 56 53 49 89 fe 49 bf 00 00 00 00 00
RSP: 0018:ffffc90003be7cf8 EFLAGS: 00010246
RAX: 000000000000002f RBX: ffffffff8d8101c0 RCX: d5a708bd91106a00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 1ffff1100f3dfcfb R08: ffffffff816e6d5c R09: fffff5200077cf41
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff8b4c57d8 R15: ffff888079efe6a8
FS:  0000555567d1a380(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f348b777130 CR3: 000000007b82d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (3507):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/13 04:09 linux-6.1.y e4d90d63d385 530e80f8 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2024/12/13 01:31 linux-6.1.y e4d90d63d385 530e80f8 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2024/12/03 14:56 linux-6.1.y e4d90d63d385 578925bc .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2023/09/14 20:40 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2026/04/26 20:25 linux-6.1.y 7c87defbd336 9c2d0995 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/01/16 15:53 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2025/10/08 12:20 linux-6.1.y 882efbdd9d34 7e2882b3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2025/06/26 04:53 linux-6.1.y 58485ff1a74f 26d77996 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2024/11/02 04:44 linux-6.1.y 7c15117f9468 f00eed24 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2024/11/02 04:10 linux-6.1.y 7c15117f9468 f00eed24 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2023/07/09 21:29 linux-6.1.y 61fd484b2cf6 668cb1fa .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2025/03/12 17:43 linux-6.1.y 6ae7ac5c4251 ee70e6db .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/26 17:15 linux-6.1.y fdb6fcb41cc7 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2026/06/25 20:34 linux-6.1.y fdb6fcb41cc7 7ff32d8b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2026/06/25 20:34 linux-6.1.y fdb6fcb41cc7 7ff32d8b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2026/06/25 06:08 linux-6.1.y fdb6fcb41cc7 cfa969bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2026/06/24 13:22 linux-6.1.y fdb6fcb41cc7 302586aa .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2026/06/24 01:12 linux-6.1.y fdb6fcb41cc7 042555ff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2026/06/23 12:43 linux-6.1.y fdb6fcb41cc7 4b1d8f01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2026/06/22 18:41 linux-6.1.y fdb6fcb41cc7 5a630be6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2026/06/22 18:41 linux-6.1.y fdb6fcb41cc7 5a630be6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
2026/06/30 16:41 linux-6.1.y fdb6fcb41cc7 00e8b0fd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/30 04:29 linux-6.1.y fdb6fcb41cc7 fff8d0a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/30 04:26 linux-6.1.y fdb6fcb41cc7 fff8d0a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/30 01:09 linux-6.1.y fdb6fcb41cc7 6a0c72dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/29 21:44 linux-6.1.y fdb6fcb41cc7 6a0c72dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/29 13:33 linux-6.1.y fdb6fcb41cc7 6a0c72dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/29 08:43 linux-6.1.y fdb6fcb41cc7 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/29 07:16 linux-6.1.y fdb6fcb41cc7 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/29 04:35 linux-6.1.y fdb6fcb41cc7 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/29 02:35 linux-6.1.y fdb6fcb41cc7 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/28 09:17 linux-6.1.y fdb6fcb41cc7 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/28 07:55 linux-6.1.y fdb6fcb41cc7 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/27 16:40 linux-6.1.y fdb6fcb41cc7 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/27 14:02 linux-6.1.y fdb6fcb41cc7 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/26 11:38 linux-6.1.y fdb6fcb41cc7 7ff32d8b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/26 00:19 linux-6.1.y fdb6fcb41cc7 7ff32d8b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/25 16:27 linux-6.1.y fdb6fcb41cc7 cfa969bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/25 07:11 linux-6.1.y fdb6fcb41cc7 cfa969bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/25 03:58 linux-6.1.y fdb6fcb41cc7 302586aa .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/24 02:15 linux-6.1.y fdb6fcb41cc7 042555ff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/23 13:07 linux-6.1.y fdb6fcb41cc7 4b1d8f01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/23 08:51 linux-6.1.y fdb6fcb41cc7 5a630be6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/23 07:06 linux-6.1.y fdb6fcb41cc7 5a630be6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/22 20:28 linux-6.1.y fdb6fcb41cc7 5a630be6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/22 14:17 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/22 09:51 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/22 07:05 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/22 05:15 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/22 00:03 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/21 22:58 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/21 20:24 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/21 18:49 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/21 16:06 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/21 10:44 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2026/06/21 02:09 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 VFS: Busy inodes after unmount (use-after-free)
2023/03/18 09:53 linux-6.1.y 7eaef76fbc46 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan VFS: Busy inodes after unmount (use-after-free)
* Struck through repros no longer work on HEAD.