Re: [syzbot] [fs?] general protection fault in pidfs_free_pid

[Christian Brauner]

On Mon, Jun 23, 2025 at 11:27:26AM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    5d4809e25903 Add linux-next specific files for 20250620
> git tree:       linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=150ef30c580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=58afc4b78b52b7e3
> dashboard link: https://syzkaller.appspot.com/bug?extid=25317a459958aec47bfa
> compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10a5330c580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12c9f6bc580000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/16492bf6b788/disk-5d4809e2.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/7be284ded1de/vmlinux-5d4809e2.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/467d717f0d9c/bzImage-5d4809e2.xz
> 
> The issue was bisected to:
> 
> commit fb0b3e2b2d7f213cb4fde623706f9ed6d748a373
> Author: Christian Brauner <brauner@xxxxxxxxxx>
> Date:   Wed Jun 18 20:53:46 2025 +0000
> 
>     pidfs: support xattrs on pidfds
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=15a1b370580000
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=17a1b370580000
> console output: https://syzkaller.appspot.com/x/log.txt?x=13a1b370580000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+25317a459958aec47bfa@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: fb0b3e2b2d7f ("pidfs: support xattrs on pidfds")

That is fixed on vfs-6.17.pidfs. :)