[syzbot] [afs?] KASAN: slab-use-after-free Read in afs_dynroot_test_super

[Christian Brauner]

On Sat, Sep 02, 2023 at 06:44:17AM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    1c59d383390f Merge tag 'linux-kselftest-nolibc-6.6-rc1' of..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=13f80797a80000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=4940ad7c14cda5c7
> dashboard link: https://syzkaller.appspot.com/bug?extid=629c4f1a4cefe03f8985
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=115b0c70680000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=170267b7a80000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/b6c588f544ac/disk-1c59d383.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/bab40745ca7b/vmlinux-1c59d383.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/9a8f42a5537c/bzImage-1c59d383.xz

#syz fix: super: ensure valid info