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-rw-r--r--arch/x86/include/asm/pkeys.h2
-rw-r--r--include/linux/pkeys.h1
-rw-r--r--mm/mprotect.c11
3 files changed, 13 insertions, 1 deletions
diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h
index 33777c291a85..666ffc862ef7 100644
--- a/arch/x86/include/asm/pkeys.h
+++ b/arch/x86/include/asm/pkeys.h
@@ -38,4 +38,6 @@ static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
unsigned long init_val);
+#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | VM_PKEY_BIT3)
+
#endif /*_ASM_X86_PKEYS_H */
diff --git a/include/linux/pkeys.h b/include/linux/pkeys.h
index 0030b4024559..6899b0bc7ce0 100644
--- a/include/linux/pkeys.h
+++ b/include/linux/pkeys.h
@@ -16,6 +16,7 @@
#define execute_only_pkey(mm) (0)
#define arch_override_mprotect_pkey(vma, prot, pkey) (0)
#define PKEY_DEDICATED_EXECUTE_ONLY 0
+#define ARCH_VM_PKEY_FLAGS 0
#endif /* ! CONFIG_ARCH_HAS_PKEYS */
#endif /* _LINUX_PKEYS_H */
diff --git a/mm/mprotect.c b/mm/mprotect.c
index dd3f40a2935f..abd9c8257b2e 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -417,6 +417,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
prev = vma;
for (nstart = start ; ; ) {
+ unsigned long mask_off_old_flags;
unsigned long newflags;
int new_vma_pkey;
@@ -426,9 +427,17 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
if (rier && (vma->vm_flags & VM_MAYEXEC))
prot |= PROT_EXEC;
+ /*
+ * Each mprotect() call explicitly passes r/w/x permissions.
+ * If a permission is not passed to mprotect(), it must be
+ * cleared from the VMA.
+ */
+ mask_off_old_flags = VM_READ | VM_WRITE | VM_EXEC |
+ ARCH_VM_PKEY_FLAGS;
+
new_vma_pkey = arch_override_mprotect_pkey(vma, prot, pkey);
newflags = calc_vm_prot_bits(prot, new_vma_pkey);
- newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
+ newflags |= (vma->vm_flags & ~mask_off_old_flags);
/* newflags >> 4 shift VM_MAY% in place of VM_% */
if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) {