syzbot


possible deadlock in cgroup_free

Status: auto-obsoleted due to no activity on 2023/12/30 03:12
Subsystems: cgroups
[Documentation on labels]
Reported-by: syzbot+cef555184e66963dabc2@syzkaller.appspotmail.com
First crash: 103d, last: 99d
Cause bisection: introduced by (bisect log) :
commit 2d25a889601d2fbc87ec79b30ea315820f874b78
Author: Peter Zijlstra <peterz@infradead.org>
Date: Sun Sep 17 11:24:21 2023 +0000

  ptrace: Convert ptrace_attach() to use lock guards

Crash: possible deadlock in cgroup_free (log)
Repro: C syz .config
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [cgroups?] possible deadlock in cgroup_free 2 (6) 2023/11/19 15:30
Last patch testing requests (3)
Created Duration User Patch Repo Result
2023/12/04 03:27 22m retest repro linux-next OK log
2023/12/04 03:27 23m retest repro linux-next OK log
2023/11/17 10:58 32m tintinm2017@gmail.com https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master OK log

Sample crash report:
========================================================
WARNING: possible irq lock inversion dependency detected
6.7.0-rc1-next-20231116-syzkaller #0 Not tainted
--------------------------------------------------------
syz-executor394/5112 just changed the state of lock:
ffffffff8cff86b8 (css_set_lock){..-.}-{2:2}, at: put_css_set kernel/cgroup/cgroup-internal.h:208 [inline]
ffffffff8cff86b8 (css_set_lock){..-.}-{2:2}, at: put_css_set kernel/cgroup/cgroup-internal.h:196 [inline]
ffffffff8cff86b8 (css_set_lock){..-.}-{2:2}, at: cgroup_free+0x7c/0x1d0 kernel/cgroup/cgroup.c:6748
but this lock took another, SOFTIRQ-unsafe lock in the past:
 (&sighand->siglock){+.+.}-{2:2}


and interrupts could create inverse lock ordering between them.


other info that might help us debug this:
 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sighand->siglock);
                               local_irq_disable();
                               lock(css_set_lock);
                               lock(&sighand->siglock);
  <Interrupt>
    lock(css_set_lock);

 *** DEADLOCK ***

3 locks held by syz-executor394/5112:
 #0: ffffffff8cc0a098 (tasklist_lock){++++}-{2:2}, at: ptrace_stop.part.0+0x2af/0x780 kernel/signal.c:2304
 #1: ffffffff8cfacf40 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline]
 #1: ffffffff8cfacf40 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2152 [inline]
 #1: ffffffff8cfacf40 (rcu_callback){....}-{0:0}, at: rcu_core+0x7cc/0x16b0 kernel/rcu/tree.c:2431
 #2: ffffffff8ce58800 (put_task_map-wait-type-override){+...}-{3:3}, at: put_task_struct include/linux/sched/task.h:135 [inline]
 #2: ffffffff8ce58800 (put_task_map-wait-type-override){+...}-{3:3}, at: put_task_struct include/linux/sched/task.h:123 [inline]
 #2: ffffffff8ce58800 (put_task_map-wait-type-override){+...}-{3:3}, at: delayed_put_task_struct+0x21e/0x2d0 kernel/exit.c:227

the shortest dependencies between 2nd lock and 1st lock:
 -> (&sighand->siglock){+.+.}-{2:2} {
    HARDIRQ-ON-W at:
                      lock_acquire kernel/locking/lockdep.c:5753 [inline]
                      lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718
                      __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
                      _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
                      spin_lock include/linux/spinlock.h:351 [inline]
                      class_spinlock_constructor include/linux/spinlock.h:530 [inline]
                      ptrace_set_stopped kernel/ptrace.c:391 [inline]
                      ptrace_attach+0x401/0x650 kernel/ptrace.c:478
                      __do_sys_ptrace+0x204/0x230 kernel/ptrace.c:1290
                      do_syscall_x64 arch/x86/entry/common.c:51 [inline]
                      do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82
                      entry_SYSCALL_64_after_hwframe+0x62/0x6a
    SOFTIRQ-ON-W at:
                      lock_acquire kernel/locking/lockdep.c:5753 [inline]
                      lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718
                      __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
                      _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
                      spin_lock include/linux/spinlock.h:351 [inline]
                      class_spinlock_constructor include/linux/spinlock.h:530 [inline]
                      ptrace_set_stopped kernel/ptrace.c:391 [inline]
                      ptrace_attach+0x401/0x650 kernel/ptrace.c:478
                      __do_sys_ptrace+0x204/0x230 kernel/ptrace.c:1290
                      do_syscall_x64 arch/x86/entry/common.c:51 [inline]
                      do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82
                      entry_SYSCALL_64_after_hwframe+0x62/0x6a
    INITIAL USE at:
                     lock_acquire kernel/locking/lockdep.c:5753 [inline]
                     lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718
                     __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
                     _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170
                     spin_lock_irq include/linux/spinlock.h:376 [inline]
                     calculate_sigpending+0x44/0xa0 kernel/signal.c:197
                     ret_from_fork+0x23/0x80 arch/x86/kernel/process.c:143
                     ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
  }
  ... key      at: [<ffffffff90b49f80>] __key.341+0x0/0x40
  ... acquired at:
   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
   _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162
   __lock_task_sighand+0xc2/0x340 kernel/signal.c:1422
   lock_task_sighand include/linux/sched/signal.h:748 [inline]
   cgroup_freeze_task+0x80/0x190 kernel/cgroup/freezer.c:160
   cgroup_freezer_migrate_task+0x1b7/0x3a0 kernel/cgroup/freezer.c:257
   cgroup_migrate_execute+0x2d3/0x1230 kernel/cgroup/cgroup.c:2580
   cgroup_attach_task+0x5a8/0x8e0 kernel/cgroup/cgroup.c:2888
   __cgroup_procs_write+0x311/0x540 kernel/cgroup/cgroup.c:5196
   cgroup_procs_write+0x26/0x50 kernel/cgroup/cgroup.c:5209
   cgroup_file_write+0x209/0x7c0 kernel/cgroup/cgroup.c:4092
   kernfs_fop_write_iter+0x33f/0x500 fs/kernfs/file.c:334
   call_write_iter include/linux/fs.h:2021 [inline]
   new_sync_write fs/read_write.c:491 [inline]
   vfs_write+0x64d/0xdf0 fs/read_write.c:584
   ksys_write+0x12f/0x250 fs/read_write.c:637
   do_syscall_x64 arch/x86/entry/common.c:51 [inline]
   do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82
   entry_SYSCALL_64_after_hwframe+0x62/0x6a

-> (css_set_lock){..-.}-{2:2} {
   IN-SOFTIRQ-W at:
                    lock_acquire kernel/locking/lockdep.c:5753 [inline]
                    lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718
                    __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
                    _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162
                    put_css_set kernel/cgroup/cgroup-internal.h:208 [inline]
                    put_css_set kernel/cgroup/cgroup-internal.h:196 [inline]
                    cgroup_free+0x7c/0x1d0 kernel/cgroup/cgroup.c:6748
                    __put_task_struct+0x10b/0x3d0 kernel/fork.c:992
                    put_task_struct include/linux/sched/task.h:136 [inline]
                    put_task_struct include/linux/sched/task.h:123 [inline]
                    delayed_put_task_struct+0x22c/0x2d0 kernel/exit.c:227
                    rcu_do_batch kernel/rcu/tree.c:2158 [inline]
                    rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2431
                    __do_softirq+0x216/0x8d5 kernel/softirq.c:553
                    invoke_softirq kernel/softirq.c:427 [inline]
                    __irq_exit_rcu kernel/softirq.c:632 [inline]
                    irq_exit_rcu+0xb5/0x120 kernel/softirq.c:644
                    sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1076
                    asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
                    __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
                    _raw_spin_unlock_irqrestore+0x31/0x70 kernel/locking/spinlock.c:194
                    spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
                    do_notify_parent_cldstop+0x557/0xb60 kernel/signal.c:2213
                    ptrace_stop.part.0+0x644/0x780 kernel/signal.c:2316
                    ptrace_stop kernel/signal.c:2255 [inline]
                    ptrace_do_notify+0x22b/0x2e0 kernel/signal.c:2390
                    ptrace_notify+0xc5/0x130 kernel/signal.c:2402
                    ptrace_report_syscall include/linux/ptrace.h:411 [inline]
                    ptrace_report_syscall_entry include/linux/ptrace.h:448 [inline]
                    syscall_trace_enter.constprop.0+0xad/0x1f0 kernel/entry/common.c:65
                    __syscall_enter_from_user_work kernel/entry/common.c:94 [inline]
                    syscall_enter_from_user_mode+0xf5/0x110 kernel/entry/common.c:112
                    do_syscall_64+0x1c/0x110 arch/x86/entry/common.c:78
                    entry_SYSCALL_64_after_hwframe+0x62/0x6a
   INITIAL USE at:
                   lock_acquire kernel/locking/lockdep.c:5753 [inline]
                   lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718
                   __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
                   _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170
                   spin_lock_irq include/linux/spinlock.h:376 [inline]
                   cgroup_setup_root+0x62c/0xa00 kernel/cgroup/cgroup.c:2138
                   cgroup_init+0x23f/0x1100 kernel/cgroup/cgroup.c:6120
                   start_kernel+0x385/0x480 init/main.c:1063
                   x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:555
                   x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:536
                   secondary_startup_64_no_verify+0x166/0x16b
 }
 ... key      at: [<ffffffff8cff86b8>] css_set_lock+0x18/0x60
 ... acquired at:
   mark_usage kernel/locking/lockdep.c:4566 [inline]
   __lock_acquire+0x13c2/0x3b10 kernel/locking/lockdep.c:5090
   lock_acquire kernel/locking/lockdep.c:5753 [inline]
   lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718
   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
   _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162
   put_css_set kernel/cgroup/cgroup-internal.h:208 [inline]
   put_css_set kernel/cgroup/cgroup-internal.h:196 [inline]
   cgroup_free+0x7c/0x1d0 kernel/cgroup/cgroup.c:6748
   __put_task_struct+0x10b/0x3d0 kernel/fork.c:992
   put_task_struct include/linux/sched/task.h:136 [inline]
   put_task_struct include/linux/sched/task.h:123 [inline]
   delayed_put_task_struct+0x22c/0x2d0 kernel/exit.c:227
   rcu_do_batch kernel/rcu/tree.c:2158 [inline]
   rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2431
   __do_softirq+0x216/0x8d5 kernel/softirq.c:553
   invoke_softirq kernel/softirq.c:427 [inline]
   __irq_exit_rcu kernel/softirq.c:632 [inline]
   irq_exit_rcu+0xb5/0x120 kernel/softirq.c:644
   sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1076
   asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
   __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
   _raw_spin_unlock_irqrestore+0x31/0x70 kernel/locking/spinlock.c:194
   spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
   do_notify_parent_cldstop+0x557/0xb60 kernel/signal.c:2213
   ptrace_stop.part.0+0x644/0x780 kernel/signal.c:2316
   ptrace_stop kernel/signal.c:2255 [inline]
   ptrace_do_notify+0x22b/0x2e0 kernel/signal.c:2390
   ptrace_notify+0xc5/0x130 kernel/signal.c:2402
   ptrace_report_syscall include/linux/ptrace.h:411 [inline]
   ptrace_report_syscall_entry include/linux/ptrace.h:448 [inline]
   syscall_trace_enter.constprop.0+0xad/0x1f0 kernel/entry/common.c:65
   __syscall_enter_from_user_work kernel/entry/common.c:94 [inline]
   syscall_enter_from_user_mode+0xf5/0x110 kernel/entry/common.c:112
   do_syscall_64+0x1c/0x110 arch/x86/entry/common.c:78
   entry_SYSCALL_64_after_hwframe+0x62/0x6a


stack backtrace:
CPU: 1 PID: 5112 Comm: syz-executor394 Not tainted 6.7.0-rc1-next-20231116-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_irq_inversion_bug.part.0+0x3e1/0x590 kernel/locking/lockdep.c:4079
 print_irq_inversion_bug kernel/locking/lockdep.c:4032 [inline]
 check_usage_forwards kernel/locking/lockdep.c:4110 [inline]
 mark_lock_irq kernel/locking/lockdep.c:4242 [inline]
 mark_lock+0x570/0xc50 kernel/locking/lockdep.c:4677
 mark_usage kernel/locking/lockdep.c:4566 [inline]
 __lock_acquire+0x13c2/0x3b10 kernel/locking/lockdep.c:5090
 lock_acquire kernel/locking/lockdep.c:5753 [inline]
 lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162
 put_css_set kernel/cgroup/cgroup-internal.h:208 [inline]
 put_css_set kernel/cgroup/cgroup-internal.h:196 [inline]
 cgroup_free+0x7c/0x1d0 kernel/cgroup/cgroup.c:6748
 __put_task_struct+0x10b/0x3d0 kernel/fork.c:992
 put_task_struct include/linux/sched/task.h:136 [inline]
 put_task_struct include/linux/sched/task.h:123 [inline]
 delayed_put_task_struct+0x22c/0x2d0 kernel/exit.c:227
 rcu_do_batch kernel/rcu/tree.c:2158 [inline]
 rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2431
 __do_softirq+0x216/0x8d5 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0xb5/0x120 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1076
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x70 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 f6 c8 e3 f6 48 89 df e8 ae 40 e4 f6 f7 c5 00 02 00 00 75 1f 9c 58 f6 c4 02 75 2f <bf> 01 00 00 00 e8 65 ee d5 f6 65 8b 05 86 19 7f 75 85 c0 74 12 5b
RSP: 0018:ffffc90003d47c68 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffff8880287d9bc0 RCX: 1ffffffff23e4388
RDX: 0000000000000000 RSI: ffffffff8accbfe0 RDI: ffffffff8b2f13e0
RBP: 0000000000000246 R08: 0000000000000001 R09: fffffbfff23e31ea
R10: ffffffff91f18f57 R11: 0000000000000003 R12: ffff8880287d9bc0
R13: ffff88801a799dc0 R14: ffffc90003d47d00 R15: 0000000000000246
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 do_notify_parent_cldstop+0x557/0xb60 kernel/signal.c:2213
 ptrace_stop.part.0+0x644/0x780 kernel/signal.c:2316
 ptrace_stop kernel/signal.c:2255 [inline]
 ptrace_do_notify+0x22b/0x2e0 kernel/signal.c:2390
 ptrace_notify+0xc5/0x130 kernel/signal.c:2402
 ptrace_report_syscall include/linux/ptrace.h:411 [inline]
 ptrace_report_syscall_entry include/linux/ptrace.h:448 [inline]
 syscall_trace_enter.constprop.0+0xad/0x1f0 kernel/entry/common.c:65
 __syscall_enter_from_user_work kernel/entry/common.c:94 [inline]
 syscall_enter_from_user_mode+0xf5/0x110 kernel/entry/common.c:112
 do_syscall_64+0x1c/0x110 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x62/0x6a
RIP: 0033:0x7fd945b5b8e7
Code: 44 00 00 48 c7 c0 b0 ff ff ff 64 c7 00 16 00 00 00 31 c0 eb b4 e8 39 46 fd ff 66 0f 1f 84 00 00 00 00 00 b8 6d 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffffab4d8d8 EFLAGS: 00000246 ORIG_RAX: 000000000000006d
RAX: ffffffffffffffda RBX: 0000555555a92700 RCX: 00007fd945b5b8e7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007fd945bbefc0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffffab4d8f4
R13: 00007ffffab4d950 R14: 00007ffffab4d990 R15: 00007fd945af9200
 </TASK>
----------------
Code disassembly (best guess):
   0:	f5                   	cmc
   1:	53                   	push   %rbx
   2:	48 8b 74 24 10       	mov    0x10(%rsp),%rsi
   7:	48 89 fb             	mov    %rdi,%rbx
   a:	48 83 c7 18          	add    $0x18,%rdi
   e:	e8 f6 c8 e3 f6       	call   0xf6e3c909
  13:	48 89 df             	mov    %rbx,%rdi
  16:	e8 ae 40 e4 f6       	call   0xf6e440c9
  1b:	f7 c5 00 02 00 00    	test   $0x200,%ebp
  21:	75 1f                	jne    0x42
  23:	9c                   	pushf
  24:	58                   	pop    %rax
  25:	f6 c4 02             	test   $0x2,%ah
  28:	75 2f                	jne    0x59
* 2a:	bf 01 00 00 00       	mov    $0x1,%edi <-- trapping instruction
  2f:	e8 65 ee d5 f6       	call   0xf6d5ee99
  34:	65 8b 05 86 19 7f 75 	mov    %gs:0x757f1986(%rip),%eax        # 0x757f19c1
  3b:	85 c0                	test   %eax,%eax
  3d:	74 12                	je     0x51
  3f:	5b                   	pop    %rbx

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/16 19:51 linux-next f31817cbcf48 cb976f63 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/16 14:16 linux-next f31817cbcf48 cb976f63 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/20 03:11 linux-next eff99d8edbed cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/19 22:34 linux-next eff99d8edbed cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/18 23:28 linux-next eff99d8edbed cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/17 07:56 linux-next eff99d8edbed cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/17 07:11 linux-next eff99d8edbed cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/17 06:35 linux-next eff99d8edbed cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/17 06:18 linux-next eff99d8edbed cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/17 05:53 linux-next eff99d8edbed cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/17 02:43 linux-next eff99d8edbed cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/16 09:28 linux-next f31817cbcf48 cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
2023/11/16 06:46 linux-next f31817cbcf48 cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in cgroup_free
* Struck through repros no longer work on HEAD.