kernel BUG in erofs_iget

[Gao Xiang]

On 2023/9/13 07:02, Sanan Hasanov wrote:
> Good day, dear maintainers,
> 
> We found a bug using a modified kernel configuration file used by syzbot.
> 
> We enhanced the coverage of the configuration file using our tool, klocalizer.

1) Please don't enable CONFIG_EROFS_FS_DEBUG=y when fuzzing.  This configuration
    is just for developper debugging, not for daily use or fuzzing.

2) Please don't use random -next version, I don't even find this version in
    https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/refs/tags
    now.  Although it seems

198 bogusimode:
199 	erofs_err(inode->i_sb, "bogus i_mode (%o) @ nid %llu",
200 		  inode->i_mode, vi->nid);
201 	err = -EFSCORRUPTED;
202 err_out:
203>	DBG_BUGON(1);
204 	kfree(copied);
205 	erofs_put_metabuf(buf);
206 	return ERR_PTR(err);

    when I check Linux v6.3 source code.  Please use upstream or latest tree for
    fuzzing, thanks!

Thanks,
Gao Xiang

> 
> Kernel Branch: 6.3.0-next-20230426
> Kernel Config: https://drive.google.com/file/d/1rGIKWTEfoMed0JL5jWFws4GJ0VNSVgw8/view?usp=sharing
> Reproducer: https://drive.google.com/file/d/1ceAFcx9hhevq_ivDNPkXmEGYsr26yB4N/view?usp=sharing
> Thank you!
> 
> Best regards,
> Sanan Hasanov
>