Re: [PATCH] hfs: fix oops on mount with corrupted btree extent records

From: Jeff Mahoney
Date: Tue Oct 13 2009 - 10:14:37 EST


On 10/13/2009 12:12 AM, Valdis.Kletnieks@xxxxxx wrote:
> On Mon, 12 Oct 2009 20:41:37 EDT, Jeff Mahoney said:
>> A particular fsfuzzer run caused an hfs file system to crash on mount. This
>> is due to a corrupted MDB extent record causing a miscalculation of
>> HFS_I(inode)->first_blocks for the extent tree. If the extent records
>> are zereod out, it won't trigger the first_blocks special case. Instead
>> it falls through to the extent code which we're still in the middle
>> of initializing.
>>
>> This patch catches the 0 size extent records, reports the corruption,
>> and fails the mount.
>
> Just for completeness - does the current fsck.hfs already know how to fix it, or
> at least heave stuff over the side so the filesystem is self-consistent again?
> Or will a user who hits this need a new fsck.hfs to get it back to mountable?

Sorry, I don't actually know. We don't ship a fsck.hfs so I haven't
tested it.

-Jeff

--
Jeff Mahoney
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/