WARNING: suspicious RCU usage in corrupted

WARNING: suspicious RCU usage in corrupted

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    036db8bd9637 Merge branch 'for-4.17-fixes' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14d187e7800000
kernel config:  https://syzkaller.appspot.com/x/.config?x=31f4b3733894ef79
dashboard link: https://syzkaller.appspot.com/bug?extid=5cec30d9329f61f2fb29
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
userspace arch: i386
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=1110de07800000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+5cec30d9329f61f2fb29@syzkaller.appspotmail.com

random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
IPVS: ftp: loaded support on port[0] = 21

=============================
WARNING: suspicious RCU usage
4.17.0-rc4+ #64 Not tainted
-----------------------------
arch/x86/kernel/traps.c:537 entry code didn't wake RCU!

other info that might help us debug this:


RCU used illegally from idle CPU!
rcu_scheduler_active = 2, debug_locks = 1
RCU used illegally from extended quiescent state!
no locks held by swapper/0/0.

stack backtrace:


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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Re: WARNING: suspicious RCU usage in corrupted

[Dmitry Vyukov]

On Wed, May 9, 2018 at 7:03 PM syzbot
<syzbot+5cec30d9329f61f2fb29@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    036db8bd9637 Merge branch 'for-4.17-fixes' of git://git.ke..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=14d187e7800000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=31f4b3733894ef79
> dashboard link: https://syzkaller.appspot.com/bug?extid=5cec30d9329f61f2fb29
> compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> userspace arch: i386
> syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=1110de07800000

This wasn't reproduced during bisection attempt, happened once a year ago.

#syz invalid

> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+5cec30d9329f61f2fb29@syzkaller.appspotmail.com
>
> random: sshd: uninitialized urandom read (32 bytes read)
> random: sshd: uninitialized urandom read (32 bytes read)
> IPVS: ftp: loaded support on port[0] = 21
>
> =============================
> WARNING: suspicious RCU usage
> 4.17.0-rc4+ #64 Not tainted
> -----------------------------
> arch/x86/kernel/traps.c:537 entry code didn't wake RCU!
>
> other info that might help us debug this:
>
>
> RCU used illegally from idle CPU!
> rcu_scheduler_active = 2, debug_locks = 1
> RCU used illegally from extended quiescent state!
> no locks held by swapper/0/0.
>
> stack backtrace:
>
>
> ---
> This bug 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 syzkaller@googlegroups.com.
>
> syzbot will keep track of this bug report.
> If you forgot to add the Reported-by tag, once the fix for this bug is
> merged
> into any tree, please reply to this email with:
> #syz fix: exact-commit-title
> If you want to test a patch for this bug, please reply with:
> #syz test: git://repo/address.git branch
> and provide the patch inline or as an attachment.
> To mark this as a duplicate of another syzbot report, please reply with:
> #syz dup: exact-subject-of-another-report
> If it's a one-off invalid bug report, please reply with:
> #syz invalid
> Note: if the crash happens again, it will cause creation of a new bug
> report.
> Note: all commands must start from beginning of the line in the email body.
>
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