Re: [BUG] Infinite loop in cleanup_mnt() task_work on 6.3-rc3

From: Calvin Owens
Date: Fri Feb 09 2024 - 23:14:04 EST


On Tuesday 02/06 at 20:50 +0000, Al Viro wrote:
> On Tue, Feb 06, 2024 at 11:52:58AM -0800, Calvin Owens wrote:
> > Hello all,
> >
> > A couple times in the past week, my laptop has been wedged by a spinning
> > cleanup_mnt() task_work from an exiting container runtime (bwrap).
>
> Check if git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git #fixes
>
> helps.

That absolutely fixes it (the revert of 57851607).

This reproducer hits the bug 100% of the time on my Debian Sid GNOME box:

$ for i in {1..1000}; do \
dd if=/dev/urandom bs=65536 count=1 status=none | \
convert -size 256x256 -depth 8 GRAY:- ${i}.png; done
$ nautilus .

It turns out Nautilus was the trigger: it spawns and destroys containers
in very quick succession to compute each thumbnail in a directory of
images.

Thanks,
Calvin