[PATCH 1/4] arm64: module: create module allocations without exec permissions

From: Ard Biesheuvel
Date: Thu May 23 2019 - 06:27:21 EST


Now that the core code manages the executable permissions of code
regions of modules explicitly, it is no longer necessary to create
the module vmalloc regions with RWX permissions, and we can create
them with RW- permissions instead, which is preferred from a
security perspective.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxx>
---
arch/arm64/kernel/module.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index 2e4e3915b4d0..88f0ed31d9aa 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -41,7 +41,7 @@ void *module_alloc(unsigned long size)

p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
module_alloc_base + MODULES_VSIZE,
- gfp_mask, PAGE_KERNEL_EXEC, 0,
+ gfp_mask, PAGE_KERNEL, 0,
NUMA_NO_NODE, __builtin_return_address(0));

if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&
@@ -57,7 +57,7 @@ void *module_alloc(unsigned long size)
*/
p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
module_alloc_base + SZ_4G, GFP_KERNEL,
- PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
+ PAGE_KERNEL, 0, NUMA_NO_NODE,
__builtin_return_address(0));

if (p && (kasan_module_alloc(p, size) < 0)) {
--
2.17.1