Re: [PATCH v2] proc: only bump parent nlink when registering directories

[Jan Kara]

Hello!

On Mon 29-06-26 14:42:17, Krzysztof Wilczyński wrote:
> > > proc_register() increments the parent directory's link count for every
> > > entry it registers, while remove_proc_entry() and remove_proc_subtree()
> > > decrement it only when the removed entry is a directory.  Regular files
> > > thus inflate the parent's count while they exist, and leak one link
> > > permanently on every create and remove cycle.
> > > 
> > > For example, /proc/bus/pci/00 with twenty-two device files and no
> > > subdirectories reports nlink 24 instead of 2, and SR-IOV VF enable
> > > and disable cycles, each creating and removing the VF config space
> > > entries under /proc/bus/pci/<bus>, inflate the link count of that
> > > directory without bound.
> > > 
> > > [...]
> > 
> > Applied to the vfs.fixes branch of the vfs/vfs.git tree.
> > Patches in the vfs.fixes branch should appear in linux-next soon.
> [...] 
> > [1/1] proc: only bump parent nlink when registering directories
> >       https://git.kernel.org/vfs/vfs/c/552864f6ac8f
> 
> I assume this got lost?  Seems its missing from 7.2-rc1, sadly.

I don't think it got lost. I'd expect Christian to send the fix for 7.2-rc2
(he merged it to his tree only during a merge window). I've checked his
tree to verify but apparently Christian didn't push out vfs.fixes or
vfs.all branch for a couple of weeks.

								Honza
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR