This is a note to let you know that I've just added the patch titled
efi: Allow EFI_MEMORY_XP and EFI_MEMORY_RO both to be cleared
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
efi-allow-efi_memory_xp-and-efi_memory_ro-both-to-be.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1fc79e90f63bf8408e4079e81df1ca5c77c7d887
Author: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Date: Fri Apr 30 16:22:51 2021 +0200
efi: Allow EFI_MEMORY_XP and EFI_MEMORY_RO both to be cleared
[ Upstream commit 45add3cc99feaaf57d4b6f01d52d532c16a1caee ]
UEFI spec 2.9, p.108, table 4-1 lists the scenario that both attributes
are cleared with the description "No memory access protection is
possible for Entry". So we can have valid entries where both attributes
are cleared, so remove the check.
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Fixes: 10f0d2f577053 ("efi: Implement generic support for the Memory Attributes table")
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/firmware/efi/memattr.c b/drivers/firmware/efi/memattr.c
index aac972b056d9..e0889922cc6d 100644
--- a/drivers/firmware/efi/memattr.c
+++ b/drivers/firmware/efi/memattr.c
@@ -69,11 +69,6 @@ static bool entry_is_valid(const efi_memory_desc_t *in, efi_memory_desc_t *out)
return false;
}
- if (!(in->attribute & (EFI_MEMORY_RO | EFI_MEMORY_XP))) {
- pr_warn("Entry attributes invalid: RO and XP bits both cleared\n");
- return false;
- }
-
if (PAGE_SIZE > EFI_PAGE_SIZE &&
(!PAGE_ALIGNED(in->phys_addr) ||
!PAGE_ALIGNED(in->num_pages << EFI_PAGE_SHIFT))) {
