[syzbot] WARNING in exit_tasks_rcu_finish

From: syzbot
Date: Sun Jun 12 2022 - 11:46:52 EST


Hello,

syzbot found the following issue on:

HEAD commit: 6d0c80680317 Add linux-next specific files for 20220610
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13b52c2ff00000
kernel config: https://syzkaller.appspot.com/x/.config?x=a30d6e3e814e5931
dashboard link: https://syzkaller.appspot.com/bug?extid=9bb26e7c5e8e4fa7e641
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

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+9bb26e7c5e8e4fa7e641@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
WARNING: CPU: 1 PID: 28639 at kernel/rcu/tasks.h:1664 exit_tasks_rcu_finish_trace kernel/rcu/tasks.h:1664 [inline]
WARNING: CPU: 1 PID: 28639 at kernel/rcu/tasks.h:1664 exit_tasks_rcu_finish+0x122/0x1b0 kernel/rcu/tasks.h:1006
Modules linked in:
CPU: 1 PID: 28639 Comm: syz-executor.3 Not tainted 5.19.0-rc1-next-20220610-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:exit_tasks_rcu_finish_trace kernel/rcu/tasks.h:1664 [inline]
RIP: 0010:exit_tasks_rcu_finish+0x122/0x1b0 kernel/rcu/tasks.h:1006
Code: fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 62 0f b6 85 89 04 00 00 83 e0 01 08 d8 74 0e <0f> 0b 5b 48 89 ef 5d 41 5c e9 00 d2 ff ff 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc9000a497b58 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000201 RCX: 1ffff11004213b89
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88802109dc49
RBP: ffff88802109d7c0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88802109dc40
R13: dffffc0000000000 R14: ffff88802109d7c0 R15: ffff88802109ddd0
FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f771379d090 CR3: 0000000051fd2000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
do_exit+0x18f2/0x2a00 kernel/exit.c:844
do_group_exit+0xd2/0x2f0 kernel/exit.c:925
get_signal+0x2542/0x2600 kernel/signal.c:2857
arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869
exit_to_user_mode_loop kernel/entry/common.c:166 [inline]
exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201
__syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f7713689109
Code: Unable to access opcode bytes at RIP 0x7f77136890df.
RSP: 002b:00007f77125fe218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f771379bf68 RCX: 00007f7713689109
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f771379bf6c
RBP: 00007f771379bf60 R08: 00007fff2278d080 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f771379bf6c
R13: 00007fff22724c8f R14: 00007f77125fe300 R15: 0000000000022000
</TASK>


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