Re: [syzbot] [hfs?] WARNING in hfs_write_inode

[Viacheslav Dubeyko <slava@dubeyko.com>]

Hi Arnd,

> On Jan 4, 2023, at 2:33 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> 
> On Wed, Jan 4, 2023, at 20:06, Linus Torvalds wrote:
>> 
>> I suspect this code is basically all dead. From what I can tell, hfs
>> only gets updates for
>> 
>> (a) syzbot reports
>> 
>> (b) vfs interface changes
> 
> There is clearly no new work going into it, and most data exchange
> with MacOS would use HFS+, but I think there are still some users.
> 
>> and the last real changes seem to have been by Ernesto A. Fernández
>> back in 2018.
>> 
>> Hmm. Looking at that code, we have another bug in there, introduced by
>> an earlier fix for a similar issue: commit 8d824e69d9f3 ("hfs: fix OOB
>> Read in __hfs_brec_find") added
>> 
>> +       if (HFS_I(main_inode)->cat_key.CName.len > HFS_NAMELEN)
>> +               return -EIO;
>> 
>> but it's after hfs_find_init(), so it should actually have done a
>> hfs_find_exit() to not leak memory.
>> 
>> So we should probably fix that too.
>> 
>> Something like this ENTIRELY UNTESTED patch?
>> 
>> Do we have anybody who looks at hfs?
> 
> Adding Viacheslav Dubeyko to Cc, he's at least been reviewing
> patches for HFS and HFS+ somewhat recently. The linux-m68k
> list may have some users dual-booting old MacOS.
> 
> Viacheslav, see the start of the thread at
> https://lore.kernel.org/lkml/000000000000dbce4e05f170f289@google.com/
> 

Let me take a look into the issue.

Thanks,
Slava.