From 68f9032e77373ab64d257699e9976f341a571b07 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 6 Jan 2020 14:35:39 +0000 Subject: arm64: Revert support for execute-only user mappings commit 24cecc37746393432d994c0dbc251fb9ac7c5d72 upstream. The ARMv8 64-bit architecture supports execute-only user permissions by clearing the PTE_USER and PTE_UXN bits, practically making it a mostly privileged mapping but from which user running at EL0 can still execute. The downside, however, is that the kernel at EL1 inadvertently reading such mapping would not trip over the PAN (privileged access never) protection. Revert the relevant bits from commit cab15ce604e5 ("arm64: Introduce execute-only page access permissions") so that PROT_EXEC implies PROT_READ (and therefore PTE_USER) until the architecture gains proper support for execute-only user mappings. Fixes: cab15ce604e5 ("arm64: Introduce execute-only page access permissions") Cc: # 4.9.x- Acked-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/pgtable-prot.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'arch/arm64/include/asm/pgtable-prot.h') diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h index f705d96a76f2..5bc3de78306a 100644 --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -77,13 +77,12 @@ #define PAGE_COPY_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN) #define PAGE_READONLY __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN) #define PAGE_READONLY_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN) -#define PAGE_EXECONLY __pgprot(_PAGE_DEFAULT | PTE_NG | PTE_PXN) #define __P000 PAGE_NONE #define __P001 PAGE_READONLY #define __P010 PAGE_COPY #define __P011 PAGE_COPY -#define __P100 PAGE_EXECONLY +#define __P100 PAGE_READONLY_EXEC #define __P101 PAGE_READONLY_EXEC #define __P110 PAGE_COPY_EXEC #define __P111 PAGE_COPY_EXEC @@ -92,7 +91,7 @@ #define __S001 PAGE_READONLY #define __S010 PAGE_SHARED #define __S011 PAGE_SHARED -#define __S100 PAGE_EXECONLY +#define __S100 PAGE_READONLY_EXEC #define __S101 PAGE_READONLY_EXEC #define __S110 PAGE_SHARED_EXEC #define __S111 PAGE_SHARED_EXEC -- cgit v1.2.3