From: Lev Olshvang <levonshe@gmail.com>
To: arnd@arndb.de
Cc: kernel-hardening@lists.openwall.com, Lev Olshvang <levonshe@gmail.com>
Subject: [RFC PATCH 4/5] X86:Prevent write to read-only pages :text, PLT/GOT tables from another process
Date: Mon, 6 Apr 2020 17:20:44 +0300 [thread overview]
Message-ID: <20200406142045.32522-5-levonshe@gmail.com> (raw)
In-Reply-To: <20200406142045.32522-1-levonshe@gmail.com>
Signed-off-by: Lev Olshvang <levonshe@gmail.com>
---
arch/x86/include/asm/mmu_context.h | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 4e55370e48e8..708135112d95 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -216,12 +216,19 @@ static inline void arch_unmap(struct mm_struct *mm, unsigned long start,
static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
bool write, bool execute, bool foreign)
{
- /* pkeys never affect instruction fetches */
+#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
+ /* Don't check PKRU since pkeys never affect instruction fetches */
if (execute)
return true;
+
/* allow access if the VMA is not one from this process */
if (foreign || vma_is_foreign(vma))
return true;
+
return __pkru_allows_pkey(vma_pkey(vma), write);
}
--
2.17.1
next prev parent reply other threads:[~2020-04-06 14:59 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-06 14:20 [RFC PATCH 0/5] Prevent write to read-only pages (text, PLT/GOT Lev Olshvang
2020-04-06 14:20 ` [RFC PATCH 1/5] security : hardening : prevent write to proces's read-only pages from another process Lev Olshvang
2020-04-06 19:15 ` Kees Cook
2020-04-07 10:16 ` Lev R. Oshvang .
2020-04-07 16:25 ` Kees Cook
2020-04-06 14:20 ` [RFC PATCH 2/5] Prevent write to " Lev Olshvang
2020-04-06 14:20 ` [RFC PATCH 3/5] Prevent write to read-only pages text, PLT/GOT tables " Lev Olshvang
2020-04-06 14:20 ` Lev Olshvang [this message]
2020-04-06 14:20 ` [RFC PATCH 5/5] UM:Prevent write to read-only pages :text, " Lev Olshvang
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