On Sat, Mar 26, 2022 at 11:41:17AM -0700, Linus Torvalds wrote:
On Sat, Mar 26, 2022 at 3:18 AM Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:"
Yes, I've been watching that thread. This change is already in 5.15 and 5.16 kernels, and does solve one known security issue, so it's a tough call.
If you're following that thread, you'll have seen that I've reverted it, and I actually think the security argument was bogus - the whole commit was due to a misunderstanding of the actual direction of the data transfer.
I see that now, thanks.
But why did you just revert that commit, and not the previous one (i.e. the one that this one "fixes")? Shouldn't ddbd89deb7d3 ("swiotlb: fix info leak with DMA_FROM_DEVICE") also be dropped?
I'm going to drop both from the 5.4 and 5.10 stable queues now, and add your revert, but I think your tree also needs the original swiotlb fix commit reverted to get back to a "known good" state.
thanks,
greg k-h