Re: [syzbot] [rcu?] WARNING in srcu_invoke_callbacks (2)

[Joel Fernandes]

On Tue, Feb 18, 2025 at 09:47:27AM -0800, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    a64dcfb451e2 Linux 6.14-rc2
> git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
> console output: https://syzkaller.appspot.com/x/log.txt?x=12398f18580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=c9c47badcd079906
> dashboard link: https://syzkaller.appspot.com/bug?extid=ae5b16688c0c675b1a1f
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> userspace arch: arm64
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/c0a862fcec77/disk-a64dcfb4.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f03793fc001b/vmlinux-a64dcfb4.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/ae71c33eae14/Image-a64dcfb4.gz.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+ae5b16688c0c675b1a1f@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 6430 at kernel/rcu/srcutree.c:1798 srcu_invoke_callbacks+0x368/0x3d8

This is weird, happens to be WARN_ON_ONCE(ready_cbs.len); in
srcu_invoke_callbacks().

Perhaps, stack corruption or the SRCU cblist's ->seglen got corrupted?

thanks,

 - Joel