syzbot


WARNING in cgroup_freeze

Status: upstream: reported C repro on 2025/10/02 05:18
Subsystems: cgroups
[Documentation on labels]
Reported-by: syzbot+27a2519eb4dad86d0156@syzkaller.appspotmail.com
Fix commit: cgroup: Fix seqcount lockdep assertion in cgroup freezer
Patched on: [ci-upstream-linux-next-kasan-gce-root ci-upstream-rust-kasan-gce], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 9d13h, last: 6h48m
Cause bisection: introduced by (bisect log) :
commit afa3701c0e45ecb9e4d160048ca4e353c7489948
Author: Tiffany Yang <ynaffit@google.com>
Date: Fri Aug 22 01:37:52 2025 +0000

  cgroup: cgroup.stat.local time accounting

Crash: WARNING in cgroup_freeze (log)
Repro: C syz .config
  
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [cgroups?] WARNING in cgroup_freeze 0 (2) 2025/10/06 16:49
[PATCH] cgroup: Fix seqcount lockdep assertion in cgroup freezer 5 (5) 2025/10/04 08:34
Last patch testing requests (3)
Created Duration User Patch Repo Result
2025/10/06 16:49 21m nirbhay.lkd@gmail.com patch upstream OK log
2025/10/02 01:48 21m kuniyu@google.com patch upstream OK log
2025/10/02 00:09 14m kuniyu@google.com patch upstream report log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 6077 at ./include/linux/seqlock.h:221 __seqprop_assert include/linux/seqlock.h:221 [inline]
WARNING: CPU: 1 PID: 6077 at ./include/linux/seqlock.h:221 cgroup_do_freeze kernel/cgroup/freezer.c:182 [inline]
WARNING: CPU: 1 PID: 6077 at ./include/linux/seqlock.h:221 cgroup_freeze+0x80a/0xf90 kernel/cgroup/freezer.c:309
Modules linked in:
CPU: 1 UID: 0 PID: 6077 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__seqprop_assert include/linux/seqlock.h:221 [inline]
RIP: 0010:cgroup_do_freeze kernel/cgroup/freezer.c:182 [inline]
RIP: 0010:cgroup_freeze+0x80a/0xf90 kernel/cgroup/freezer.c:309
Code: 90 e9 9e fb ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c e7 f9 ff ff 4c 89 f7 e8 e1 43 67 00 e9 da f9 ff ff e8 17 68 06 00 90 <0f> 0b 90 e9 10 fc ff ff 44 89 f9 80 e1 07 38 c1 48 8b 0c 24 0f 8c
RSP: 0018:ffffc900049878e0 EFLAGS: 00010293
RAX: ffffffff81b6c6b9 RBX: 0000000000000000 RCX: ffff888034d49e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90004987a70 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d6d127 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000001 R15: ffff88803220e791
FS:  0000555575731500(0000) GS:ffff888127117000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31763fff CR3: 0000000048326000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 cgroup_freeze_write+0x156/0x1c0 kernel/cgroup/cgroup.c:4174
 cgroup_file_write+0x39e/0x740 kernel/cgroup/cgroup.c:4312
 kernfs_fop_write_iter+0x3ad/0x540 fs/kernfs/file.c:352
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5d2/0xb40 fs/read_write.c:686
 ksys_write+0x14b/0x260 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6039a3eec9
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:00007ffee96dd818 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6039c95fa0 RCX: 00007f6039a3eec9
RDX: 0000000000000012 RSI: 0000200000000200 RDI: 0000000000000004
RBP: 00007f6039ac1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6039c95fa0 R14: 00007f6039c95fa0 R15: 0000000000000003
 </TASK>

Crashes (344):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/02 05:21 upstream 080ffb4bec4d 267f56c6 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
2025/10/01 10:02 upstream 50c19e20ed2e 65a0eece .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
2025/10/01 09:08 upstream 50c19e20ed2e 65a0eece .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
2025/10/01 08:27 upstream 50c19e20ed2e 65a0eece .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/01 08:13 upstream 50c19e20ed2e 65a0eece .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
2025/10/10 11:31 upstream 5472d60c129f ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/10 11:31 upstream 5472d60c129f ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/10 03:04 upstream 18a7e218cfcd 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/10 00:34 upstream 18a7e218cfcd 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 23:28 upstream 18a7e218cfcd 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 21:38 upstream 18a7e218cfcd 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 21:38 upstream 18a7e218cfcd 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 18:33 upstream ec714e371f22 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 16:44 upstream ec714e371f22 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 13:41 upstream ec714e371f22 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 10:57 upstream ec714e371f22 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 09:39 upstream ec714e371f22 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 08:28 upstream ec714e371f22 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 08:14 upstream ec714e371f22 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 05:56 upstream ec714e371f22 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/09 04:43 upstream cd5a0afbdf80 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
2025/10/08 22:49 upstream 0d97f2067c16 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/08 20:37 upstream 0d97f2067c16 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
2025/10/08 19:16 upstream 0d97f2067c16 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/08 16:08 upstream 0d97f2067c16 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/08 03:27 upstream 971199ad2a0f 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/07 23:34 upstream 971199ad2a0f 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
2025/10/07 18:24 upstream 971199ad2a0f 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
2025/10/07 17:13 upstream c746c3b51698 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/07 16:41 upstream c746c3b51698 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/07 15:13 upstream c746c3b51698 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/07 12:24 upstream c746c3b51698 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/07 09:58 upstream c746c3b51698 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/07 07:46 upstream c746c3b51698 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
2025/10/07 07:09 upstream c746c3b51698 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
2025/10/07 05:51 upstream c746c3b51698 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/07 01:46 upstream fd94619c4336 91305dbe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/06 22:07 upstream fd94619c4336 91305dbe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/06 10:35 upstream 7a405dbb0f03 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/06 09:07 upstream 7a405dbb0f03 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/06 07:37 upstream 7a405dbb0f03 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/05 20:50 upstream 6093a688a07d 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
2025/10/05 15:58 upstream 6093a688a07d 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/05 11:37 upstream d104e3d17f7b 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/05 10:28 upstream d104e3d17f7b 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/05 08:12 upstream d104e3d17f7b 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/05 08:06 upstream d104e3d17f7b 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in cgroup_freeze
2025/10/05 07:02 upstream d104e3d17f7b 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in cgroup_freeze
* Struck through repros no longer work on HEAD.