On Tue 14-07-20 14:31:22, Jan Kara wrote: > On Mon 13-07-20 19:14:47, Ritesh Harjani wrote: > > > > > > On 7/13/20 6:28 PM, Jan Kara wrote: > > > From: Wolfgang Frisch <wolfgang.frisch@xxxxxxxx> > > > > > > When extent tree is corrupted we can hit BUG_ON in > > > ext4_es_cache_extent(). Check for this and abort caching instead of > > > crashing the machine. > > > > Was it intentionally made corrupted by crafting a corrupted disk image? > > I'm not sure how Wolfgang hit the issue. I'd expect some fs image > fuzzing... Wolfgang? > > > Are there more such logic in place which checks for such corruption at other > > places? > > That's a good question. But now that I'm looking at it ext4_ext_check() > should actually catch a corruption like this. It is only the path in > ext4_find_extent()->ext4_cache_extents() that can face the issue so > probably instead of a fix in ext4_cache_extents() we should rather add more > careful extent info checks for the extents contained directly in the inode. > I'll look into it. I was checking this more and indeed the problem can actually happen only with the journal inode because that is special-cased when checking extent tree. I'll send a new series that fixes this in a cleaner way. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
