Re: [syzbot] [hfs?] kernel BUG in may_open (3)

From: Christian Brauner

Date: Mon Jan 12 2026 - 04:27:19 EST


On Mon, Jan 12, 2026 at 12:51:33AM -0800, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: b6151c4e60e5 Merge tag 'erofs-for-6.19-rc5-fixes' of git:/..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15d45922580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=7b058fb1d7dbe6b1
> dashboard link: https://syzkaller.appspot.com/bug?extid=f98189ed18c1f5f32e00
> 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=14a7d19a580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16a2f19a580000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/6eb5179ada01/disk-b6151c4e.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/bc48d1a68ed0/vmlinux-b6151c4e.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/061d4fb696a7/bzImage-b6151c4e.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/df739de73585/mount_0.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+f98189ed18c1f5f32e00@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> loop0: detected capacity change from 0 to 1024
> VFS_BUG_ON_INODE(!IS_ANON_FILE(inode)) encountered for inode ffff8880384b01e0
> fs hfsplus mode 0 opflags 0x4 flags 0x0 state 0x70 count 2

This is hfsplus adding inodes with a non-valid mode.