Re: [syzbot] [fs?] WARNING in copy_mnt_ns

From: Jan Kara
Date: Thu Oct 02 2025 - 04:44:01 EST


On Wed 01-10-25 13:18:33, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 50c19e20ed2e Merge tag 'nolibc-20250928-for-6.18-1' of git..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=126f605b980000
> kernel config: https://syzkaller.appspot.com/x/.config?x=8f1ac8502efee0ee
> dashboard link: https://syzkaller.appspot.com/bug?extid=e0f8855a87443d6a2413
> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1374b858580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15602092580000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/5fb1f87b20e9/disk-50c19e20.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/aebfd0341e80/vmlinux-50c19e20.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/11452a5eed6c/bzImage-50c19e20.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+e0f8855a87443d6a2413@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> ------------[ cut here ]------------
> ida_free called for id=1019 which is not allocated.

Please try attached patch:

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR