syzbot


WARNING in css_rstat_exit

Status: upstream: reported syz repro on 2025/06/13 16:55
Subsystems: cgroups
[Documentation on labels]
Reported-by: syzbot+8d052e8b99e40bc625ed@syzkaller.appspotmail.com
Fix commit: eea51c6e3f66 cgroup: avoid null de-ref in css_rstat_exit()
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-snapshot-upstream-root 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-linux-next-kasan-gce-root ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce], missing on: [ci-qemu-native-arm64-kvm ci-qemu2-riscv64 ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-usb]
First crash: 72d, last: 2d23h
Discussions (4)
Title Replies (including bot) Last reply
[PATCH cgroup/for-6.16-fixes] cgroup: avoid null de-ref in css_rstat_exit() 2 (2) 2025/08/09 18:46
[PATCH cgroup/for-6.16-fixes] cgroup: avoid null de-ref in css_rstat_exit() 2 (2) 2025/08/01 17:38
Re: [PATCH 0/5 cgroup/for-6.16-fixes] harden css_create() for safe placement of call to css_rstat_init() 2 (2) 2025/07/28 18:04
[syzbot] [cgroups?] WARNING in css_rstat_exit 8 (14) 2025/07/22 00:29
Last patch testing requests (4)
Created Duration User Patch Repo Result
2025/07/15 01:05 20m inwardvessel@gmail.com patch upstream OK log
2025/07/15 00:56 0m inwardvessel@gmail.com patch upstream error
2025/07/14 23:58 0m inwardvessel@gmail.com patch upstream error
2025/07/14 23:37 0m inwardvessel@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 347e9f5043c89695b01e66b3ed111755afcf1911 error

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 43 at kernel/cgroup/rstat.c:497 css_rstat_exit+0x368/0x470 kernel/cgroup/rstat.c:497
Modules linked in:
CPU: 1 UID: 0 PID: 43 Comm: kworker/1:1 Not tainted 6.16.0-rc7-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: cgroup_destroy css_free_rwork_fn
RIP: 0010:css_rstat_exit+0x368/0x470 kernel/cgroup/rstat.c:497
Code: 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 0e 01 00 00 49 c7 85 70 05 00 00 00 00 00 00 e9 00 ff ff ff e8 b9 09 07 00 90 <0f> 0b 90 e9 3e ff ff ff e8 ab 09 07 00 90 0f 0b 90 e9 30 ff ff ff
RSP: 0018:ffffc90000b37bc0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88801e2f3400 RCX: ffff88812472d000
RDX: ffff888022ad3c00 RSI: ffffffff81b44b17 RDI: ffffffff8df34da0
RBP: ffff88801e2f3408 R08: 0000000000000005 R09: 0000000000000007
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88801e2f3420
R13: 0000000000000000 R14: 0000000000000003 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88812482d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3035ffff CR3: 0000000034f18000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 css_free_rwork_fn+0x80/0x12e0 kernel/cgroup/cgroup.c:5449
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (39):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/21 17:51 upstream 89be9a83ccf1 56d87229 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/07/14 07:29 upstream 5d5d62298b8b 3cda49cf .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/21 15:43 upstream 32b7144f806e 3e79b825 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/21 15:42 upstream 32b7144f806e 3e79b825 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/20 02:25 upstream b19a97d57c15 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/19 23:11 upstream b19a97d57c15 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/18 10:20 upstream c17b750b3ad9 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/18 10:16 upstream c17b750b3ad9 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/18 07:40 upstream 8d561baae505 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/18 03:43 upstream 8d561baae505 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/18 03:39 upstream 8d561baae505 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/17 15:10 upstream 99bade344cfa 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/17 13:26 upstream 99bade344cfa 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/17 01:22 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/16 23:14 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/16 21:35 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/16 21:32 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/16 21:29 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/16 15:19 upstream dfd4b508c8c6 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/16 04:25 upstream dfd4b508c8c6 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/14 10:26 upstream 0cc53520e68b 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/13 14:23 upstream 8742b2d8935f 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/13 07:49 upstream 8742b2d8935f 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/12 09:27 upstream 53e760d89498 c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/12 02:04 upstream 8f5ae30d69d7 c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/10 23:50 upstream 2b38afce25c4 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/08/10 09:57 upstream 561c80369df0 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in css_rstat_exit
2025/07/21 15:31 upstream 89be9a83ccf1 56d87229 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/07/20 10:19 upstream f4a40a4282f4 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/07/18 15:59 upstream 6832a9317eee f550e092 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/07/18 13:18 upstream 6832a9317eee f550e092 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/07/16 02:34 upstream 155a3c003e55 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/07/15 16:06 upstream 155a3c003e55 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/07/14 17:28 upstream 347e9f5043c8 d8fc7335 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/07/14 05:57 upstream 5d5d62298b8b 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/07/13 12:18 upstream 3f31a806a62e 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/07/13 12:17 upstream 3f31a806a62e 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in css_rstat_exit
2025/06/13 12:06 upstream 27605c8c0f69 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in css_rstat_exit
2025/08/03 06:49 upstream eacf91b0c78a 7368264b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64 WARNING in css_rstat_exit
* Struck through repros no longer work on HEAD.