On Wed, 20 Sep 2023 05:09:58 +0100 "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> wrote:
> In order to fix the L1TF vulnerability, x86 can invert the PTE bits for
> PROT_NONE VMAs, which means we cannot move from one PTE to the next by
> adding 1 to the PFN field of the PTE. Abstract advancing the PTE to
> the next PFN through a pte_next_pfn() function/macro.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Fixes: bcc6cc832573 ("mm: add default definition of set_ptes()")
> Reported-by: syzbot+55cc72f8cc3a549119df@xxxxxxxxxxxxxxxxxxxxxxxxx
Is it just me, or is it a pain hunting down things via message IDs?
I tweaked the changelog thusly, pointing out that this fixes a BUG.
: In order to fix the L1TF vulnerability, x86 can invert the PTE bits for
: PROT_NONE VMAs, which means we cannot move from one PTE to the next by
: adding 1 to the PFN field of the PTE. This results in the BUG reported at
: [1].
:
: Abstract advancing the PTE to the next PFN through a pte_next_pfn()
: function/macro.
:
: Link: https://lkml.kernel.org/r/20230920040958.866520-1-willy@xxxxxxxxxxxxx
: Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
: Fixes: bcc6cc832573 ("mm: add default definition of set_ptes()")
: Reported-by: syzbot+55cc72f8cc3a549119df@xxxxxxxxxxxxxxxxxxxxxxxxx
: Closes: https://lkml.kernel.org/r/000000000000d099fa0604f03351@xxxxxxxxxx [1]
