On Mon, 31 Jan 2022 20:02:55 -0300 Mauricio Faria de Oliveira <mfo@xxxxxxxxxxxxx> wrote: > Problem: > ======= > > Userspace might read the zero-page instead of actual data from a > direct IO read on a block device if the buffers have been called > madvise(MADV_FREE) on earlier (this is discussed below) due to a > race between page reclaim on MADV_FREE and blkdev direct IO read. > > ... > > Fixes: 802a3a92ad7a ("mm: reclaim MADV_FREE pages") Five years ago. As it doesn't seem urgent I targeted 5.18-rc1 for this, and added a cc:stable so it will trickle back into earlier trees. How does this plan sound?