Thread (30 messages) 30 messages, 3 authors, 2017-06-27

[RFC v3 11/23] x86: key creation with PKEY_DISABLE_EXECUTE is disallowed

From: Ram Pai <hidden>
Date: 2017-06-22 01:40:22
Also in: linux-arch, linux-mm, lkml
Subsystem: the rest, x86 architecture (32-bit and 64-bit) · Maintainers: Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen

x86 does not support disabling execute permissions on a pkey.

Signed-off-by: Ram Pai <redacted>
---
 arch/x86/kernel/fpu/xstate.c | 3 +++
 1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index c24ac1e..d582631 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -900,6 +900,9 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 	if (!boot_cpu_has(X86_FEATURE_OSPKE))
 		return -EINVAL;
 
+	if (init_val & PKEY_DISABLE_EXECUTE)
+		return -EINVAL;
+
 	/* Set the bits we need in PKRU:  */
 	if (init_val & PKEY_DISABLE_ACCESS)
 		new_pkru_bits |= PKRU_AD_BIT;
-- 
1.8.3.1
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