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From: Lev Olshvang <levonshe@gmail.com>
To: keescook@chromium.org
Cc: kernel-hardening@lists.openwall.com, Lev Olshvang <levonshe@gmail.com>
Subject: [PATCH v4 2/2] Hardening x86: Forbid writes to read-only memory pages of a process
Date: Thu, 16 Apr 2020 18:59:17 +0300	[thread overview]
Message-ID: <20200416155917.28536-3-levonshe@gmail.com> (raw)
In-Reply-To: <20200416155917.28536-1-levonshe@gmail.com>

Signed-off-by: Lev Olshvang <levonshe@gmail.com>
---
 arch/x86/include/asm/mmu_context.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 4e55370e48e8..e9b820780424 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -216,6 +216,11 @@ 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)
 {
+	if (unlikely(!vma_write_allowed(vma, write, foreign))) {
+		pr_err_once("Error : PID[%d] %s writes to read only memory\n",
+			    current->pid, current->comm);
+		return false;
+	}
 	/* pkeys never affect instruction fetches */
 	if (execute)
 		return true;
-- 
2.17.1


      parent reply	other threads:[~2020-04-16 16:00 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-16 15:59 [PATCH v3 0/5] hardening : prevent write to proces's read-only pages Lev Olshvang
2020-04-16 15:59 ` [PATCH v4 1/2] hardening : prevent write to read-only pages of user process Lev Olshvang
2020-04-16 15:59 ` Lev Olshvang [this message]

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