VFS: Busy inodes after unmount (use-after-free) (4)

Status: upstream: reported C repro on 2025/12/25 14:06
Subsystems: jfs
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+d569e274f46ca86f78fa@syzkaller.appspotmail.com
First crash: 280d, last: 13m
Cause bisection: failed (error log, bisect log)
  
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
b44cccbd assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ VFS: Busy inodes after unmount (use-after-free) (4) 2026/05/25 09:46 2026/05/25 09:46 2026/05/25 10:59 c69befb3
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] jfs: Check for discrepancies between iag and inomap iagctl 2 (2) 2026/02/08 08:20
[syzbot] [jfs?] VFS: Busy inodes after unmount (use-after-free) (4) 0 (3) 2025/12/29 20:43
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 syz, C 4 1234d 1289d 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 syz, C error 277 372d 484d 29/29 fixed on 2025/09/04 16:57
linux-6.1 VFS: Busy inodes after unmount (use-after-free) origin:lts-only 2 syz, C inconclusive 5381 20m 1269d 0/3 upstream: reported C repro on 2023/03/18 09:53
android-5-15 VFS: Busy inodes after unmount (use-after-free) origin:downstream 2 syz, C error done 2 1187d 1289d 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 syz, C done inconclusive 1 1289d 1289d 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 syz, C inconclusive 1133 1h24m 404d 0/2 upstream: reported C repro on 2025/07/29 23:52
upstream VFS: Busy inodes after unmount (use-after-free) (3) fs 2 syz, C error 85 312d 341d 29/29 fixed on 2025/11/18 08:45
upstream VFS: Busy inodes after unmount (use-after-free) fs 2 syz, C error 55684 489d 1321d 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 syz, C done 3738 12m 1268d 0/3 upstream: reported C repro on 2023/03/19 11:46
Last patch testing requests (8)
Created Duration User Patch Repo Result
2026/06/10 03:25 45m retest repro upstream log
2026/04/23 01:32 22m retest repro upstream report log
2026/04/22 10:19 1h07m retest repro upstream report log
2026/03/31 23:29 52m retest repro upstream report log
2026/01/30 07:30 16m retest repro upstream report log
2026/01/11 12:39 22m retest repro upstream report log
2025/12/29 20:43 24m zlatistiv@gmail.com patch upstream OK log
2025/12/27 16:54 21m zlatistiv@gmail.com patch upstream OK log

Sample crash report:
tblock:ffffc900031d9420: ffffffff ffffffff 98be3920 ffffffff
tblock:ffffc900031d9430: 00000000 00000000 00000000 00000000
tblock:ffffc900031d9440: 8aeb3a20 ffffffff 00000200 00000000
tblock:ffffc900031d9450: 00000000 00000000 00000000 00000000
tblock:ffffc900031d9460: 00000000 00000000 98da0d80 ffffffff
tblock:ffffc900031d9470: 00000000 00000000 00000000 00000000
tblock:ffffc900031d9480: 8b252b20 ffffffff 00000300 00000000
tblock:ffffc900031d9490: 031d9490 ffffc900 031d9490 ffffc900
tblock:ffffc900031d94a0: 5a2a2b40 ffff8880 00000000 00000000
VFS: Busy inodes after unmount of loop3 (jfs)
------------[ cut here ]------------
kernel BUG at fs/super.c:653!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 5940 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:generic_shutdown_super+0x2bc/0x2c0 fs/super.c:651
Code: 03 42 80 3c 28 00 74 08 4c 89 f7 e8 ee e4 f2 ff 49 8b 16 48 81 c3 c8 07 00 00 48 c7 c7 20 2e f9 8a 48 89 de e8 95 55 f8 fe 90 <0f> 0b 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f
RSP: 0018:ffffc9000522fd00 EFLAGS: 00010246
RAX: 000000000000002d RBX: ffff8880237107c8 RCX: c4ed90b584a6ed00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffff110046e211a R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000a45f51 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff8d9ef560 R15: ffff8880237108d0
FS:  0000555563a75500(0000) GS:ffff888126def000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9506f8b000 CR3: 000000003a252000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 kill_block_super+0x44/0x90 fs/super.c:1722
 deactivate_locked_super+0xbc/0x130 fs/super.c:474
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
 task_work_run+0x1d4/0x260 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0xef/0x4e0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fda2a450a77
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffd9e375fd8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000064 RCX: 00007fda2a450a77
RDX: 0000000000000200 RSI: 0000000000000009 RDI: 00007ffd9e377180
RBP: 00007fda2a4d3d7d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffd9e377180
R13: 00007fda2a4d3d7d R14: 0000555563a754a8 R15: 00007ffd9e378250
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:generic_shutdown_super+0x2bc/0x2c0 fs/super.c:651
Code: 03 42 80 3c 28 00 74 08 4c 89 f7 e8 ee e4 f2 ff 49 8b 16 48 81 c3 c8 07 00 00 48 c7 c7 20 2e f9 8a 48 89 de e8 95 55 f8 fe 90 <0f> 0b 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f
RSP: 0018:ffffc9000522fd00 EFLAGS: 00010246
RAX: 000000000000002d RBX: ffff8880237107c8 RCX: c4ed90b584a6ed00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffff110046e211a R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000a45f51 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff8d9ef560 R15: ffff8880237108d0
FS:  0000555563a75500(0000) GS:ffff888126def000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9506f8b000 CR3: 000000003a252000 CR4: 00000000003526f0

Crashes (1743):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/25 22:49 upstream ccd1cdca5cd4 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs VFS: Busy inodes after unmount (use-after-free)
2025/12/25 14:05 upstream ccd1cdca5cd4 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/04/08 09:33 upstream 3036cd0d3328 2c961e87 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/07 15:22 upstream df2908090cda 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/07 14:01 upstream df2908090cda 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/07 08:32 upstream df2908090cda 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/07 08:13 upstream df2908090cda 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/07 07:15 upstream df2908090cda 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/07 07:08 upstream df2908090cda 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/07 00:59 upstream df2908090cda 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/07 00:43 upstream df2908090cda 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/06 18:36 upstream 1fc5a74b108f 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/06 13:07 upstream 1fc5a74b108f 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/06 10:15 upstream 1fc5a74b108f 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/06 10:06 upstream 1fc5a74b108f 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/06 01:01 upstream 214f4aeb2255 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 23:34 upstream 214f4aeb2255 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 20:46 upstream 0d9ff90a5422 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 20:05 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 19:53 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 17:10 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 13:48 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 12:50 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 07:29 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 06:09 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 06:03 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 00:19 upstream bc35965f6940 3f042c7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 00:13 upstream bc35965f6940 3f042c7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/04 22:33 upstream bc35965f6940 3f042c7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/04 20:40 upstream bc35965f6940 3f042c7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/04 17:47 upstream bc35965f6940 3f042c7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/04 01:48 upstream 841e384b841a 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/04 01:26 upstream 841e384b841a 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/03 22:04 upstream 841e384b841a 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/03 10:45 upstream 940de590b839 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/03 10:45 upstream 940de590b839 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/03 09:01 upstream 940de590b839 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root VFS: Busy inodes after unmount (use-after-free)
2026/09/03 07:31 upstream 940de590b839 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/03 04:43 upstream 940de590b839 85995287 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/08/03 20:51 upstream 075b74841bd0 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs VFS: Busy inodes after unmount (use-after-free)
2026/09/05 04:49 upstream 654ae5d73c05 4f7b22a0 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root VFS: Busy inodes after unmount (use-after-free)
2026/09/04 10:01 upstream 8ab1afb2eb24 801f0966 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root VFS: Busy inodes after unmount (use-after-free)
2026/09/04 07:50 upstream 8ab1afb2eb24 801f0966 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root VFS: Busy inodes after unmount (use-after-free)
2026/09/07 16:10 linux-next 9d80aa4617b3 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/07 04:38 linux-next 9d80aa4617b3 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/07 04:27 linux-next 9d80aa4617b3 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/06 04:05 linux-next 9d80aa4617b3 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/06 02:28 linux-next 9d80aa4617b3 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/09/05 10:48 linux-next 9d80aa4617b3 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2025/12/01 13:24 linux-next 7d31f578f323 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root VFS: Busy inodes after unmount (use-after-free)
2026/01/16 01:17 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 59e4d31a0470 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 VFS: Busy inodes after unmount (use-after-free)
* Struck through repros no longer work on HEAD.