BUG: spinlock bad magic in ptrace_may_access

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11346782b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=36b4f9a6624d5a74efb4
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+36b4f9...@syzkaller.appspotmail.com

BUG: spinlock bad magic on CPU#1, syz-executor.3/452
lock: 0xffff8880001007d0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: -1
CPU: 1 PID: 452 Comm: syz-executor.3 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
do_raw_spin_lock+0x19f/0x220 kernel/locking/spinlock_debug.c:112
spin_lock include/linux/spinlock.h:329 [inline]
task_lock include/linux/sched/task.h:147 [inline]
ptrace_may_access+0x20/0x50 kernel/ptrace.c:361
__do_sys_perf_event_open kernel/events/core.c:10653 [inline]
__se_sys_perf_event_open+0x1cbb/0x2720 kernel/events/core.c:10549
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fc7449f3ae9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc741f69188 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fc744b06f60 RCX: 00007fc7449f3ae9
RDX: fffffffffffffffc RSI: 0000000000000000 RDI: 000000002001d000
RBP: 00007fc744a4df25 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd7f129eff R14: 00007fc741f69300 R15: 0000000000022000
list_del corruption. next->prev should be ffff88822ce11358, but was 0000000000000000
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:54!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 451 Comm: syz-executor.3 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__list_del_entry_valid.cold+0x48/0x4a lib/list_debug.c:54
Code: e8 ec 42 f7 ff 0f 0b 4c 89 e2 48 89 ee 48 c7 c7 e0 e3 b3 88 e8 d8 42 f7 ff 0f 0b 48 89 ee 48 c7 c7 a0 e4 b3 88 e8 c7 42 f7 ff <0f> 0b 41 83 c7 01 b8 ff ff 37 00 44 89 3d 5a 85 3a 05 48 c1 e0 2a
RSP: 0018:ffff88822b3efca8 EFLAGS: 00010086
RAX: 0000000000000054 RBX: ffff88822ce10280 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff814dff01 RDI: ffffed104567df87
RBP: ffff88822ce11358 R08: 0000000000000054 R09: 0000000000000000
R10: 0000000000000005 R11: ffffffff8c66505b R12: ffff88804e3095d8
R13: ffff888000101118 R14: 0000000000000000 R15: 1ffff1104567dfa4
FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000052f25000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__list_del_entry include/linux/list.h:117 [inline]
list_del_init include/linux/list.h:159 [inline]
css_set_move_task+0xf0/0x570 kernel/cgroup/cgroup.c:823
cgroup_exit+0x114/0x4b0 kernel/cgroup/cgroup.c:5718
do_exit+0xc0b/0x2be0 kernel/exit.c:882
do_group_exit+0x125/0x310 kernel/exit.c:967
__do_sys_exit_group kernel/exit.c:978 [inline]
__se_sys_exit_group kernel/exit.c:976 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:976
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fc7449f3ae9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd7f12a128 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007fc7449f3ae9
RDX: 00007fc7449a672b RSI: ffffffffffffffbc RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000001 R14: 0000000000000001 R15: 00007ffd7f12a210
Modules linked in:
---[ end trace 9f6c5eada1266d4b ]---
RIP: 0010:__list_del_entry_valid.cold+0x48/0x4a lib/list_debug.c:54
Code: e8 ec 42 f7 ff 0f 0b 4c 89 e2 48 89 ee 48 c7 c7 e0 e3 b3 88 e8 d8 42 f7 ff 0f 0b 48 89 ee 48 c7 c7 a0 e4 b3 88 e8 c7 42 f7 ff <0f> 0b 41 83 c7 01 b8 ff ff 37 00 44 89 3d 5a 85 3a 05 48 c1 e0 2a
RSP: 0018:ffff88822b3efca8 EFLAGS: 00010086
RAX: 0000000000000054 RBX: ffff88822ce10280 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff814dff01 RDI: ffffed104567df87
RBP: ffff88822ce11358 R08: 0000000000000054 R09: 0000000000000000
R10: 0000000000000005 R11: ffffffff8c66505b R12: ffff88804e3095d8
R13: ffff888000101118 R14: 0000000000000000 R15: 1ffff1104567dfa4
FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000052f25000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.