[RFC PATCH 2/5] Prevent write to read-only pages from another process

Lev Olshvang
2020-04-06T14:57:26Z

arch/unicore32/include/asm/mmu_context.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/unicore32/include/asm/mmu_context.h b/arch/unicore32/include/asm/mmu_context.h
index 388c0c811c68..caf240b8a748 100644
--- a/arch/unicore32/include/asm/mmu_context.h
+++ b/arch/unicore32/include/asm/mmu_context.h
@@ -92,7 +92,12 @@ static inline void arch_unmap(struct mm_struct *mm,
static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
bool write, bool execute, bool foreign)
{
+#ifdef CONFIG_PROTECT_READONLY_USER_MEMORY
+ /* Forbid write to PROT_READ pages of foreign process */
+ if (write && foreign && (!(vma->vm_flags & VM_WRITE)))
+ return false;
+#endif
/* by default, allow everything */
return true;
}
-#endif
+#endif /*__UNICORE_MMU_CONTEXT_H__*/
--
2.17.1