Re: Re: [PATCH] ext4: Fix KASAN use-after-free in ext4_find_extent

[余昊铖]

Hi,

Sorry but I am a bit confused by your words. My original fuzz tesing already enabled CONFIG_BLK_DEV_WRITE_MOUNTED as in most major Linux distributions. 

So does a bug found when CONFIG_BLK_DEV_WRITE_MOUNTED is enabled still hold value for reporting? Should I enable or disable this configuration in my future fuzzing work?

Thanks,
Haocheng Yu

> > Hi,
> >
> > I have disabled CONFIG_BLK_DEV_WRITE_MOUNTED and spent some time trying to trigger the reported KASAN issues. And I found neither of the two bugs has been observed since. Is this issue still worth investigating?
> 
> That essentially confirms the issue is caused by bypassing the
> filesystem to write directly to the raw disk. This is a known
> issue and is quite tricky to solve.
> 
> You can work around this specific class of issues in your fuzz
> testing by enabling CONFIG_BLK_DEV_WRITE_MOUNTED. Syzbot runs
> with this configuration enabled by default.
> 
> 
> Cheers,
> Baokun